Author: experimeads

Aeration: Forced 02 in Carboys, US-05

Oxygen is critical for fermentation! In a side by side test, this experiment tests the implications of an additional forced O2 additions at 24 hours in a traditional session mead fermented with US-05. How important is O2 for fermentation, and what are the implications of not adding it?

Yeast requires a great deal of oxygen during the “lag phase” when it is rapidly multiplying as it is critical for cell wall health. Yeast needs between 8 and 10 parts per million (ppm) of oxygen.  A level of 8 ppm is achievable using air alone (which is 21% oxygen), but a higher level can only be achieved using pure oxygen.

There are three basic methods for aerating wort:

  1. Shaking – Splashing the wort around in the fermentor can add sufficient oxygen. As long as there is enough headspace, you can get up to 8 ppm of oxygen for shaking aggressively for two minutes.
  2. Stirring – Agitation is done by stirring rapidly with a whisk for several minutes, often making a vortex and splashing. Generally, a sterilized wine degasser whip is best if you have open access to the wort.  There is some concern that you can only get up to 6 ppm of oxygen, but it will depend on time, etc.
  3. Injection – There are many ways to inject air or oxygen directly into the must, using bubbling or a carbonation stone or aeration stone at the end of the tube and wand.  You can use an inexpensive aquarium pump with an inline sterile filter or an actual oxygen bottle and regulator to inject oxygen.  Both can achieve the 8 ppm aeration level.

I prefer fermenting in buckets or in wide mouth 7 gallon wide mouth plastic carboys and agitate aggressively with a wine whip when mixing. Then, I agitate aggressively with the lid off to degas, which mixes in more 02 over the first two to three days. I’ve had great success with this method. Initially, I degassed less and added a short pure 02 addition at 24 hours, but I got away from this to avoid the cleaning of the O2 wand step but still made sure to agitate when degassing and didn’t notice much of a difference between using a stone or not. However, for many of the experiments, I ferment smaller batches in plastic water jugs. This does not allow for aggressive agitation with a wine whip or oxygen transfer, so instead I shake the jugs for two minutes at the start to try to get the 02 into solution. Reportedly, this is supposed to add sufficient 02 to the solution. I wasn’t using pure O2 because I got away from it when using buckets. However, I began noticing some small lager-like sulfur character in these carboy ferments. I designed this experiment to tests whether it could be coming from the oxygenation methods.

In this bench trial experiment, a forced 02 addition at 24 hours was tested for its flavor and aroma contributions in a 5% ABV, carbonated, dry traditional mead fermented using US-05. Both meads were aerated before pitch by aggressively stirring with a wine whip for three minutes. The treatment was an additional O2 addition using pure O2 and a diffusion stone at 24 hours. All other variables were kept the same. Both meads were presented in triangle tests in front of two judges. Judges were asked to determine the odd mead out and provided preference and tasting notes.

Recipe: 4.5%, Dry Traditional Short Mead, 2021, two 10.5 liter musts in 15 water jugs

  • 9-liters of spring water
  • 1.17 kg of white honey, clover and alfalfa, from Peace Valley Apiaries
  • 2 x green 15-gallon spring water jugs
  • 0.8 grams of calcium chloride
  • 0.3 grams of Himalayan sea salt
  • 1/5 packet or 4.9 grams of US-05 yeast

Treatment:

  • 2 min of forced 02 at 24 hours with a diffusion stone, low flow, no big bubbles

Nutrients (calculated using The MeadMakr BatchBuildr):

  • YAN Recommended: 57.7-low; 78.3 – medium, 108.7- high
    • Fermaid-K: 1.7 grams for 10.5 liters (16.5 ppm YAN)
    • DAP: 3.2 grams for 10.5 liters (65.5 ppm YAN)
    • No Go-ferm
    • Total ppm YAN from DAP and K = 82 (~medium level)

Specs at time 0:

  • Target OG: 1.035
  • pH 7.00

Mixing Notes

  • Mixed honey, water, salts aggressively for two minutes with wine whip, aerating with whip
  • Sprinkled yeast on top of must, swirled in after 20 minutes

Fermentation Notes

The inorganic nutrients were split into three additions and given at 4, 24 and 48 hours.

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

TimeO2No 02
+0h
65°F
7 pH
1.035
7 pH
1.035
+1d
65.2°F
5.06 pH
1.031
Raw honey, candy like
4.91 pH
1.031
Raw honey, candy like
+2d
65.6°F
3.62 pH
1.024
honey, candy, clean
3.57 pH
1.024
honey, candy, clean
+3d
65.3°F
3.38 pH
1.016
honey, candy, clean
3.19 pH
1.018
honey, candy, clean
+4d
65°F
3.19 pH
1.011
honey, candy, clean, bright  
3.08 pH
1.011
honey, candy, clean, less bright  
+6d
66°F
3.01 pH
1.003
3.00 pH
1.005
+7d
66°F
3.14 pH
1.000
honey, candy, clean, bright  
3.06 pH
1.001
honey, candy, clean, slightly lower note, less bright

Fermentation Comments

I’m actually a bit surprised how similar these fermentations were. There were minor differences in the pH and activity, within the range of measurement error. That said, the mead with 02 treatment did seem to maintain a higher pH. Only on day four did I start to detect any differences in aroma. The mead with treatment kept smelling of bright and fresh throughout, whereas the mead without 02 starting smelling a bit more muddled and less bright. It did not, however, give off any strong off-flavor aromas.

Secondary

The meads for testing were racked into 1 gallon carboys on day 9. They were bottled at 4 weeks from pitch, using honey to 2.5 vol. The meads had dropped clear. The mead with O2 had notes of very light honey and was clean. The mead with no 02 also had light honey character but was somehow less sweet and some lager-like sulfur character.

Tasting Notes

Meads were tested at 8 months. Two judges were blind to the treatment, and the meads were served in six consecutive triangle tests in random order, and with a random odd mead out, in identical cups. Judges were asked to guess the odd mead out and provide brief tasting notes and preference rankings.

There was a significant difference between the two meads. In 10 of the 12 triangle tests, participants could identify the odd mead out. The null hypothesis that the results were from random guessing is rejected with 99.99 percent confidence. Both participants preferred the mead with 02 treatment, but the sample size to too small to tests for significance of preference. Here is a summary of the results:

Both judges, thought the mead with treatment was clean and honey like. One judged noted the floral character. The first judge thought the no 02 mead had lager-like aroma, and sulfur – like egg – was noted after swallowing. The second judge thought the no 02 mead was stinky and not good.

Both judges were mostly making their choices mainly by smelling. The second judge was preferring not to drink the no-02 mead, describing it as rank. The sulfur was quite strong, and the second judge was noting that it was lingering in their nose and resulting in having a harder time telling the clean mead apart.


Final Notes
I tasted the meads when serving the triangle tests. The mead with the 02 treatment was a perfect mead for me, and I really liked the subtle honey-like character and was very clean. It would also make a really good base mead for other flavors. I dumped the no O2 mead. I was surprised how much sulfur was in there during pouring, since it did not seem that dramatic during fermentation or bottling.

This experiment was really insightful for me. When I think of sulfur off-flavors, I would think about yeast stress from improper YAN/ over pitching, or temperature drops. Now I know that it can also arise from improper oxygenation, another critical nutrient. Now I can provide more informed feedback when judging.

Note that I did not shake the jugs for two minutes at the beginning, but just aerated with a wine whip. Shaking is known to add more 02 into solution. However, as I have also got slight sulfur character when shaking for two minutes, I am beginning to think that there needs to be later introductions of 02 during fermentation as the 02 is not available for later generations of yeasts. I am starting to either open ferment for the first two or three days or adding a pure 02 addition at 24 hours. However, the plan is to put this to a more inclusive bench trial to test when to add and when is too much.

I also did not add Go-ferm. Yeast can substitute the amino acids in Go-ferm for oxygen in building cell walls. I’ve noted in other bench trails that the use of Go-ferm eliminates the slight sulfur character when fermenting in carboys without the 24 hour O2 addition. It seems that there could be some interplay between the amino acids in Go-ferm and 02 additions. At least in this experiment, I can see that the later 02 addition gave a very clean mead even when I did not use Go-ferm.

After this experiment, I tried a few batches where I added 02 when using buckets/ wide mouth jugs, but then starting getting far too much yeast growth when also degassing and aerating with a wine whip resulted in some sluggish ferments. I’ve since gone back to only degassing and aerating with a wine whip when using buckets/ wide mouth jugs and adding the 02 when fermenting in carboys. Maybe this is why mead makers often prefer to ferment in buckets (or course, other than cleaning and handling fruit)?

Take away: pay attention to 02. Now, for my session meads recipes, I recommend:

  1. if using a bucket/ large mouth carboy sufficient 02 can be added by taking the lid off and aggressively mixing with a wine whip two or three times a day for the first two to four days. If you’re not degassing aggressively or open fermenting, it’s best to give a pure 02 addition at 24 hours.
  2. if using jugs for primary fermentation, shaking each of them for 2 minutes aggressively at start. Then either open ferment by covering the opening with a paper towel or coffee filter and elastic band for the first three or four days or add a pure 02 addition at 24 hours.

That said, given how important later O2 additions seem to be, more bench trials are warranted.

Go-ferm Pitch Rate Off-flavor Threshold: Inorganic

In the article on Tailored Additional of Nutrients with Go-ferm (TANG 2.0), I documented that adding Go-ferm at the recommended 1.25 grams per gram of dry yeast can quickly result in excess nutrients for session meads if the pitch rate is much above the recommended 1 gram per gallon of dry yeast. Then, in the high vs low pitch rate with Go-ferm triangle test experiment, it was found that a five gram per gallon pitch rate with the recommended amount of Go-ferm resulted in significant off-flavors when compared to a 1 gram per gallon pitch rate. However, this begged an important question: what is the pitch rate threshold for which Go-ferm off-flavors are perceived?

In this bench trial experiment, alternative amounts of Go-ferm and pitch rates were testing for their flavor and aroma contributions in a 4.5% ABV, carbonated, dry traditional mead fermented using S-04. Five Go-ferm amounts/ pitch rates were tested on identical musts. Each batch was fermented side-by-side and treated identically. Given the number of meads, all five meads were presented in a bench trials in front of two judges. Judges were asked to provided feedback and rank the meads.

Recipe: 4.5%, Dry Traditional Short Mead, April. 2021, 8 liter must, split into 1.7 liter batches

  • 7-liters of spring water
  • 1 kg of white honey, clover and alfalfa, from Peace Valley Apiaries
  • 0.5 g of cal. chloride
  • 0.25 g of gypsum
  • 0.2 g of Himalayan sea salt
  • S-04 yeast

Go-ferm variations:

  • 2.5 gram per gallon yeast pitch rate, no Go-ferm
  • 2.5 gram per gallon yeast pitch rate, 1.25 g/gal Go-ferm
  • 2.5 gram per gallon yeast pitch rate with 1.25 grams per gram yeast pitch rate of Go-ferm
  • 3.5 gram per gallon yeast pitch rate with 1.25 grams per gram yeast pitch rate of Go-ferm
  • 4.5 gram per gallon yeast pitch rate with 1.25 grams per gram yeast pitch rate of Go-ferm

Nutrients (calculated using The MeadMakr BatchBuildr):

  • YAN Recommended: 57.7-low; 78.3 – medium, 108.7- high
  • Medium-low YAN level provided excluding Go-ferm
    • Fermaid-K: 0.56 grams/ gallon (15.8 ppm YAN)
    • DAP: 1.02 grams/ gallon (61.2 ppm YAN)
    • Total ppm YAN from DAP and K = 77
  • Regimes
    1. No Go-ferm: 0 additional, 77 ppm YAN total
    2. 1.25 g/gal Go-ferm: 39.7 additional, 116.7 ppm YAN total
    3. 2.5-gram pitch w Go-ferm: 103 additional, 180 ppm YAN total
    4. 3.5-gram pitch w Go-ferm: 180.25 additional, 257.25 ppm YAN total
    5. 4.5-gram pitch w Go-ferm: 231.75 additional, 308.75 ppm YAN total

Notice how quickly the ppm YAN provided increases when you increase the pitch rate and are still providing the 1.25 grams of Go-ferm per gram of dry yeast, also graph above. While Scott Labs handbooks recommend providing a higher level of YAN when the pitch rate increases we can see that even at the 2.5 grams per gallon pitch rate the total YAN is already 180 ppm YAN, higher than even the high nutrient requirement. The pitch rate of 2.5 grams per gallon is the mid-range of the 2-3 grams recommended by the yeast manufacture, so such a pitch rate for dry ale yeast is warranted. Moreover, at the 2.5 gram per gallon pitch rate, The MeadMakr BatchBuildr does already warn of excess nutrients off-flavors from an equivalent amount of Fermaid-O.

Specs at time 0:

  • Target OG: 1.035
  • pH 7.00

At pitch

  • Mixed honey, water, salts
  • Transferred to fermentors, added needed Goferm.
  • Shook jugs for two minutes
  • Sprinkled yeast on top of must
  • First nutrient addition at 3 hours

Fermentation Notes

The inorganic nutrients were split into four additions and given at 3, 18, 36 and 48 hours.

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

Time  2.5 g pitch, no go-ferm2.5 g pitch, 1.25 g/gal go-ferm2.5-gram pitch rate w go-ferm3.5-gram pitch rate w go-ferm4.5-gram pitch rate w go-ferm
+24h am 63.7°F pm 63.1°FUnfermented honeyUnfermented honeyUnfermented honeyUnfermented honeyUnfermented honey/yeast
+48h am 63.5°F pm 65.2°FSlight phenolic/ mothball honey
1.023
3.85 pH
Clean, honey, muddled apple 1.024
3.90 pH
Clean, honey, yeasty
1.022
3.93 pH
Yeasty
1.019
3.74 pH
Yeasty
1.019
3.93 pH
+3d
am 65.8°F pm 64.9°F
Clean, honey, muddled apple 1.013
3.39 pH
Clean, honey, bright apple 1.013
3.38 pH
Clean, honey, apple, yeasty 1.009
3.43 pH
Clean, honey, muddled apple, slight yeasty, slight alcohol
1.006
3.40 pH
Apple, slight go-ferm, slight alcohol
1. 006
3.56 pH
+4d
am 63.9°F pm 67.4°F
Clean, bright apple
1.006
3.24 pH
Pear, slight alcohol
1.008
3.35 pH
Pear, slight alcohol
1.005
3.38 pH
Pear, clean, yeasty 1.002
3.39 pH
Low pear, go-ferm,
1.002
3.53 pH
+5d
pm 65.8°F
Apple, honey, clean
1.003
3.32 pH
Pear, slight alcohol,
1.003
3.32 pH
Pear/apple, alcohol,
1.002
3.38 pH
Pear, honey, clean, 0.999
3.44 pH
Pear, alcohol 0.999
3.53 pH
+7d
am 66.2°F pm 67.3°F
Apple, clean 1.002
3.30 pH
Apple/pear, slight alc
1.002
3.32 pH
Pear, clean 1.000
3.38 pH
  
+8d
pm 67.7°F
Apple, honey, clean
0.999
3.32 pH
Apple, honey, clean
0.999
3.32 pH
Apple, honey, clean, alcohol 0.999
3.40 pH
  

Comments on Fementation

I really got my nose in during the fermentation to smell for aroma. Interesting, no Go-ferm had some phenolics at day 2, but it quickly cleaned up. The 1.25 g/gal Go-ferm has pretty clean aroma descriptors throughout, whereas the higher pitch rates did have yeastiness described at some point. The 3.5 and 4.5 pitch rates finished fermentation on day 5 but the lower pitch rates/ Go-ferm finished on day 8. I am a bit surprised that the first three finished at the same time.

Secondary

  • Most meads had dropped clear so transferred directly from primary to bottling
  • Carbonated with 3.6 grams/ 500ml of clover honey

Tasting Notes

Meads were tested at 4 months. Judges were blind to the treatment, and the meads were served all at once in random order in identical looking cups.

Judges were asked to provide brief tasting notes and rank from best to worst.

Time  2.5 g pitch, no go-ferm2.5 g pitch, 1.25 g/gal go-ferm2.5-gram pitch rate w go-ferm3.5-gram pitch rate w go-ferm4.5-gram pitch rate w go-ferm
Judge 1Clean, apple, slightly lager-like   Ranked 2nd Apple, clean  

Ranked 1st
Apple, clean, slightly bitter   Ranked 3rdTart, yeasty, bitter  
Ranked 4th
Tart, bitter, Umami   Ranked 5th
Judge 2Flat, not tart   Ranked 3rdBalanced, neutral  
Ranked 1st
Balanced, neutral  
Ranked 2nd
Yeasty, tart   Ranked 4thReally yeasty, tart  
Ranked 5th

Both judges ranked the 1.25 g/gal Go-ferm first in preference. This amount is consistent with the Scott Labs 1 gram per gallon pitch rate recommendation at this ABV level for wine yeasts. Judges were split between the no Go-ferm and the 2.5 gram pitch rate with the recommended amount of Go-ferm. The first judge thought the no Go-ferm was slightly better then the 2.5 gram pitch rate with the recommended amount of Go-ferm, whereas the other judge ranked those two in reverse order. The mead without the Go-ferm was also described as flat and being slightly lager like, which I interpret as a very slight sulfur character. The 3.5 and 4.5 grams per gallon pitch rate was described as bitter, yeasty, and umami flavors. Bitterness was also described for the 2.5 gram pitch rate with the recommended amount of Go-ferm by one Judge. Interestingly, tartness was described for the high pitch rates despite them finishing at a higher pH. I wonder if the meads picked up souring bacteria because of high residual YAN. It would be interesting to test the YAN and organisms hypothesis in a lab.


Final Notes

In the high vs low pitch rate with Go-ferm experiment, it was found that a five gram per gallon pitch rate with the recommended amount of Go-ferm resulted in significant off-flavors when compared to a 1 gram per gallon pitch rate. Here, the evidence suggests that the pitch rate threshold for the off-flavor occurred at pitch rates above 2.5 grams per gallon.

A couple of things I would do differently next time. First, I provided a medium level of YAN. However, another experiment showed that S-04 presented better with a low-level of compared to a high level of nutrients. I would like to try this again if it is found that a low nutrient requirement is also preferred to medium levels of YAN. Second, I gave four nutrient additions before 48 hours, and the experiment on nutrient timing that was done after showed that three additions are preferred to four.

Take away: for me, 1.25 g/gal Go-ferm showed preference over no Go-ferm and using the recommended amount for Go-ferm at normal ale yeast pitch rates and higher rates. It seems that at pitch rates above and maybe around 2.5 grams per gallon you can start to detect off-flavors from Go-ferm. Now, for my session meads recipes, I recommend adding 5 grams of Go-ferm in my 4 gallon batches.

These findings provide continued evidence that online calculators need to change. The MeadMakr BatchBuildr recommends rounding to 5 gram packets and adding 6.25 grams of Go-ferm per gallon for one gallon batches at this ABV level which is clearly inconsistent with recommendations and these findings. Moreover, allowing for high pitch rates and still recommending the standard amount of Go-ferm should probably come with a warning on Mead Made Right (current pitch rates range from 1-10 grams per gallon of dry yeast). Both of these websites are great, I use them and recommend them all the time, but there is still room for improvement.

To follow up, this experiment should be repeated with other yeasts, with fully organic nutrients, and at different ABV levels. My hypothesis for fully organic nutrients would be that the pitch rate threshold is even lower because Go-ferm already contains organic sources nutrients.

Acid Additions in a Traditional Mead

In this experiment, the use of malic acid is tested for its flavor and aroma contributions in a 4.5% ABV, carbonated, dry traditional mead fermented using S-04. The mead was fermented in one batch, then split between two identical secondary vessels and one was given the acid treatment. Other than the acid treatment, all other variables were identical. Triangle tests are conducted to see if participants can correctly identify the difference between the two meads. Respondents also provided feedback on the differences perceived in the two meads.

Acidity is one of the key parts of balance in a mead, alongside sweetness and tannin. While big fruit bomb meads have acid from the fruits, there is very little acid in honey and traditional musts often start at a pH of 7.0 before fermentation. In sweet traditional meads, the acid may help cut through the sweetness and provide balance. In a dry mead, it is a little less clear if acid is needed, as if carbonated, the carbonic acid provides brightness and there is little to no sweetness to cut. Does malic acid additions to a dry traditional brighten it up or dry it out, maybe both?

As far as I can tell, there is almost no research on the taste contribution of alternative acids in meads. Balance of Sour, Cook’s Science (May 2017) provides a nice summary in cocktails and summarizes some of the acids that are commonly used and why. Common acids that mead and winemakers can find and use are citric, malic, and tartaric acid which are purchased in a powder form. Typically, I use add acid to taste and use the acid that is appropriate for the fruit that I am using or to bring out a particular perception. The predominate acid in various fruits differs; citric acid is predominate in citrus fruits, i.e. lemons and limes, malic acid is predominate in apples, and tartaric is predominate in grapes. Someone really needs to do a comparison of the perception of different acids in meads.

This is a sister experiment to the Acid additions in a TANG cream soda mead. In that experiment, while not enough participants were able to distinguish between the two meads for the results to be statistically significant, all participants who were able to distinguish a difference preferred the mead treated with acid and the preferences were significant. In that experiment, positive descriptors of the mead treated with acid was brighter, more complex, cleaner, fuller and more mouthfeel. However, that was in a cheery vanilla mead and I expect the acid really helped hit the right note on the fruit character.

Personally, I sometimes use a bit of malic acid in short traditional because I am looking to brighten the mead up. However, I have pulled back on acid additions and add much less than I used too. Part of this is because I have dialed in high carbonation around 2.5 vol which does provide quite a bit of brightness. My hypothesis was that treatment with acid would brighten the mead up and lead to more perceived sweetness. This is based on evidence from the experiments to the Acid additions in a TANG cream soda mead. However, I did not have a prior on the preferences and was unsure what people would prefer.

Recipe: 4.5%, Dry Traditional Short Mead, Jan. 2021, 16.5 liters

  • OG = 1.034
  • 1 liter of 2020 dark, last harvest, wildflower Honey from Nith Valley apiaries
  • 0.5 kg of creamed, organic, raw, Peace River honey
  • 15 liter spring water
  • 7 gallon Fermonster fermentor
  • 1.5 grams of calcium chloride
  • 0.5 grams of Himalayan sea salt
  • 11.5 gram packet of S-04
  • 0.5 grams of ascorbic acid
  • 1 gram of malic acid

Treatment:

  • 0.25 grams malic acid per gallon

Nith Valley late season darker honey tasting notes:

  • Low floral
  • Low perceived sweetness, not overtly honey like
  • Muddled caramel, minerality
  • Low acid
  • Low mixed herbal/woody, some foamed milk (alfalfa)

Nutrients (calculated using The MeadMakr BatchBuildr):

  • Recommended nutrient level is 78 ppm YAN for medium level
  • Actual: 73 ppm YAN (medium level, scaled up due to high pitch rate)
    • Fermaid-K: 2.3 grams (contibuted 13 ppm YAN)
    • DAP: 4.3 grams (contibuted 60 ppm YAN)

At pitch

  • Mixed honey, water, salts.
  • Sprinkled yeast on top of must

Fermentation Notes

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

  • +time 0, Mixed honey, water salts. Sprinkled yeast on must. Must is 64.6°F, pH 7.0.
  • +2 hours, fed all nutrients upfront with 2.3g of Fermaid-k and 4.3 g of DAP.
  • +1 days, active fermentation, 66.6°F
  • +2 days, degassed. Smells like apples. 66.1°F
  • +3 days, degassed, 66.5°F , 1.012
  • +4 days, 66.2°F , 1.002, smells of pear, apple.
  • +5 days, 65.6°F, fermentation slowing, smells like honey, apple. 1.000
  • +7 days, 65.6°F, FG 1.000. Racked into secondary. Added 0.12 g of ascorbic acid per gallon.

Secondary

  • Bottled after another week to 2.5 volumes (primed with honey).

Both meads looked the same when bottling.

Water profile 

The mineral profile of the spring water, contribution of the salt additions and the final water profile was as follows.

Initial Tasting Notes

At bottling, I was a bit disappointed with the character of the mead. They had a mild lager-like aroma. There was some nice apples esters and fermented honey character, but they were slightly muddled by the slight sulfur. I attribute this to not using Go-ferm, and just replying on aerating with a wine whip instead of by shaking or using pure 02.

Triangle Tests 

Due to Covid-19, and in consultation with statisticians, every participant was sent two bottles and completed up to five triangle tests. Participants were sent four or five experiments and knew that I was testing something around nutrient regimes, clarifying agents, and acidity levels. The bottles were labeled experiment A, B, C etc as well as being labeled as treatment or baseline. Every participant was also sent enough identical red solo cups.

One scoresheet was filled out by each participant for each experiment. Participants were asked their experience level with meads, how blown their palate was, and their status as judges and home/professional brewers. Experience was given a value from one to five where one is first time having a mead to five being well-experienced. Palate was given a value from one to five where one is having had nothing to drink yet, and five was that they’ve already had too much (like just drank an IPA and sitting in a brewery). Participants were asked to say which mead they preferred and just select one if they couldn’t tell the difference.

There were 5 participants, each completed five triangle tests, so there were 25 triangle tests completed overall. We had a good selection of mead experts and mead enthusiasts. There were one BJCP certified beer judges and two BJCP mead judges.

On average, people were experienced with meads and their palate was not tired. All had some experience with meads and off flavors. Basic summary statistics on the self reporting of participants experience and palate when taking the triangle tests:

All responses were collected when the meads were 6-8 months old.

Results

There was a significant difference between the two meads. In 18 of the 25 triangle tests, participants could identify the odd mead out. The null hypothesis that the results were from random guessing is rejected with 99.99 percent confidence. However, four of the five participants preferred the mead with acid added, and the one participant said they preferred the mead without acid “but not by much.” The null hypothesis of equal preference between the meads is unable to be rejected, which is really not that surprising at this sample size. Even if all participants preferred the mead with acid, we could only reject the null that they are equally preferred with 93.7 percent confidence. Here is a summary of the results:

I did five triangle tests and got three right. One person only got one triangle tests correct, another got 4 out of five, and two got all five triangle test correct. No time fixed effects were significant. What people described as the difference between the two meads and the percent of correct answers is shown in the table below.

In general, the tasting notes were consistent. The no acid mead was described by two participants as being more flat, and another described it as more bland. The mead with acid was described as brighter, more pop, and two others noting acidity as the difference.

Participant three thought the mead with malic acid was more apple forward, which may be due to the use of S-04 yeast, which has apple like esters, combined with the malic acid which is predominate in pomme fruits. Participant three also thought the acid mead had muted aroma and no minerality. In contrast, the same participant described the no acid mead as having some minerality and having fresh honey character. They also thought the mead with acid was dryer, whereas the mead without acid was drying on the back palate.

What’s interesting for me if that I had thought that brighter would mean more perceived sweetness, but one of the participants noted more brightness in addition to being dryer.

Conclusion

One of the most interesting outcomes of the experiment is that the meads were significantly different. Thus, treatment with malic acid is shown in sensory analysis to not be neutral. I wish I had got a few more participants to do the triangle tests, as the number was too low to show significance of the preference.

The base mead was the same that was used in Kieselsol and Chitosan in a Traditional Mead experiment. In that experiment, there was lower perceived acid from treating with Kieselsol and Chitosan and preferences were split despite being able to detected apart. I had hypothesized that the acidity of the baseline mead may have been perceived to be too high by some participants due to the added malic acid. However, the baseline mead has the same acid treatment as this experiment and the results of this experiment suggest that this was not the case. It is now more likely that it is due to just be lower aroma and flavor.

The flavor descriptors are similar to the sister experiment to the Acid additions in a TANG cream soda mead. In that experiment, all participants who were able to distinguish a difference preferred the mead treated with acid, and the preferences were significant. In that experiment, positive descriptors of the mead treated with acid was brighter. Now, there is some evidence for me that this character may not just be desirable merely in a melomel, but also in a traditional.

I have recommended the optional use of malic acid in the Short Mead Recipes. The current recommendation is for 0.5 grams per 5 gallons, whereas 1.25 grams was used here. Based on these results, I will keep this recommendation for the traditional. It would be interesting to do a bench trial on the levels of acid and the perceived differences to dial the level in. Either way, now we have some descriptors and evidence to help inform that optional call.

Peer Reviews:

The methodology comments from the referees in the high versus low nutrient level experiment also pertain to the method used for this article. This includes: 1) Justin Angevaare, PhD, Statistician, author of p-value calculator and award-winning homebrewerhttps://onbrewing.comand 2) Chris Kwietniowski, award-winning home brewer, participant. 

Peer review 1, Tim Richards, home brewer:

Nice experiment. I use .6 grams of malic per gallon and .2 grams citric for my traditional short meads. Mine usually have a starting gravity of 1.045 and I also carbonate to 2.5 volumes. I may try a side by side with more malic to see if I have a preference. I use liquid ale yeast Wyeast 1056 and I usually back sweeten to 1.008. I really enjoy your experiments. Please keep them coming.

Additional peer reviews to follow.

Staggered Nutirent Timing in Session Meads – Inorganic

Nutrient timing is complicated in session meads as standard staggered nutrient regimes are designed for standard meads, and session meads complete fermentation much more quickly. Moreover, with inorganic nutrients, it is possible to burn yeast with DAP during the lag phase, which can result in phenolic off-flavors. In this bench trial, we test: what is the best staggered nutrient timing for session meads?

In this bench trial experiment, alternative inorganic nutrient timings were testing for their flavor and aroma contributions in a 4.5% ABV, carbonated, dry traditional mead fermented using S-04. Six alternative nutrient timings were tested on identical musts at the same time and treated identically. Given the number of meads, all six meads were presented in a bench trials in front of two judges. Judges were asked to provided feedback and rank the meads.

Recipe: 4.5%, Dry Traditional Short Mead, April. 2021, 1.7 liter batches

  • 7-liters of spring water
  • 1 kg of white honey, clover and alfalfa, from Peace Valley Apiaries
  • 0.75 g of cal. chloride
  • 0.35 g of gypsum
  • 1 g of kph03
  • 0.25 g of Himalayan sea salt
  • 2.5 gram per gallon of S-04

Nutrient timing variations:

  • All upfront
  • Day 0.2, 1, 2
  • Day 0.2, 1, 2, 3
  • Day 1,2
  • Day 0.5, 1, 1.5
  • Day 0.5, 1, 1.5, 2

Nutrients (calculated using The MeadMakr BatchBuildr):

  • YAN Recommended: 57.7-low; 78.3 – medium; 108.7 – high
  • Medium-low YAN level excluding go-ferm
    • Fermaid K: 0.56 grams/ gallon (15 ppm YAN)
    • DAP: 1.02 grams/ gallon (57 ppm YAN)
    • Goferm 2.35 grams/ gallon (73 ppm YAN)
  • Total YAN: 145 ppm YAN

Specs at time 0:

  • Target OG: 1.034
  • pH 7.00

At pitch

  • Mixed honey, water, salts, Goferm.
  • Sprinkled yeast on top of must
  • First nutrient addition at 4 hours

Fermentation Notes

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

Time 66.5°FUpfront0.2,1,20.2,1,2,31,20.5,1,1.50.5,1,1.5,2
+1d am
68.9°F
Clean, honeyClean, honeyClean, unfermented honeyClean, unfermented honeyClean, unfermented honeyClean, unfermented honey
+1d pm 66.3°FPear, apple Light phenolics
3.54 pH
1.023
Pear, apple, honey
4.39 pH
1.026
Honey, yeasty
4.65 pH
1.029
Sulfur, unfermented honey, yeast
5.60 pH
1.029
Honey, slight mothball
5.10 pH
1.032
Honey, unfermented honey
4.84 pH
1.032
+2d am 68.5°FPear
3.46 pH
1.018  
Apple, honey,
3.55 pH
1.020  
Slight sulfur, apple, honey

3.78 pH
1.021  
Honey, phenolics
4.23 pH
1.025  
Honey, pear, apple
3.96 pH
1.021  
Honey, pear
3.82 pH
1.020
+2dpm 65.6°F  
+3d am 65.8°F
Honey, pear, apple
3.51 pH
1.015
Pear, apple 3.77 pH
1.020
Honey, apple
3.87 pH
1.020
phenolics Muddled apple,
4.54 pH
1.022
Honey, apple, phenolics,
3.56 pH
1.018  
Muddled pear
3.82 pH
1.020
+3d pm 65.2°Fpear, apple
3.33 pH
1.012
phenolics
3.18 pH
1.012
Honey, muddled apple, alcohol
3.41 pH
1.015
Phenolics/ mothball
3.43 pH
1.015
Apple, alcohol 3.29 pH
1.012
Muddled pear, apple
3.19 pH
1.013
+4d pm 65.1 °F 
+5d am 68.2°F
pear, apple, honey
3.46 pH
1.008
Phenolics, apple, pear
3.28 pH
1.007
mothball
3.30 pH
1.009
apple
3.34 pH
1.007
Apple
3.30 pH
1.006
Apple, pear, honey
3.17 pH
1.008
+5d pm 65.5 °F
+6d pm 70.2°F
pear, apple, honey
3.24 pH
1.006
apple, light alcohol
3.11 pH
1.005
Apple, pear, alcohol
3.12 pH
1.004
Muddled apple
3.45 pH
1.005
Clean Apple, pear, light alcohol
3.35 pH
1.004
Clean, Apple, pear, honey
3.24 pH
1.005
+6d pm 65.0°F  
+7d am 66.7°F
pear, honey
3.31 pH
1.003
Alcohol, light apple
3.33 pH
1.001
Watery, apple 3.29 pH
1.003
Alcohol, pear
3.29 pH
1.001
Alcohol, pear 3.13 pH
1.003
Apple, pear, honey
3.07 pH
1.004
+7d pm 66.7°F   Heavy pear, alcohol
3.14 pH
0.999
Alcohol, apple
3.05 pH
0.999
pear, apple
3.13 pH
0.999
Alcohol, apple
3.35 pH
0.999
apple, pear
3.23 pH
0.999
Apple, honey
3.19 pH
0.999

Comments on Fementation

I really got my nose in during the fermentation to smell for aroma. Interesting, upfront at four hours saw some phenolics at day 1, but it quickly cleaned up. Almost all had some muddled pomme or expressed some phenolics at some point. The nutrients added at 24 and 48 hours put off sulfur, suggesting that waiting 24 hours is too long. Some of the additions that went into two days and especially three days did put off some phenolics. Day two is when the meads hit the 1.022 or 1/3 sugar break hit. It was clear you didn’t want to go much beyond that, similar to standard meads. My impression from fermentation was that the day 0.5,1,1.5,2 threw off the least phenolics, so my hypothesis is that it would do better in the bench trials. 

Secondary

  • Most meads had dropped clear so transfered directly from primary to botttling
  • Carbonated with 3.6 grams/ 500ml of white honey

Tasting Notes

Meads were tested at 2 months. Judges were asked to provide brief tasting notes and rank from best to worst.

Nutrient TimingJudge 1Judge 2
UpfrontAroma: strongest aroma of pear and apple, clean.
Taste: Clean, balanced, some diacetyl
Rank: 3rd
Overall: most flavor, depth, best
Rank: 1st
1,2Aroma: diacetyl-butterscotch, slight funk
Taste: apple, bright
Rank: 4th
Overall: bitter, yeasty, bready
Rank: 6th
0.2,1,2,3Aroma: slight funk, DMS, apple
Taste: diacetyl, flat
Rank: 6th
Overall: more yeasty
Rank: 4th
0.2,1,2Aroma: apple, pear, clean, low funk
Taste: slight bitterness, butterscotch
Rank: 2nd
Overall: yeasty, clean apple
Rank: 3rd
0.5,1,1.5Aroma: very clean, bright apple
Taste: very clean pear, no funk
Rank: 1st
Overall: clean, light apple
Rank: 2nd
0.5,1,1.5,2Aroma: some sulfur funk
Taste: bitter, muddled pear, flat, less bright/flat
Rank: 5th
Overall: bitter
Rank: 5th


Final Notes

It was surprising to me how different the profiles of the mead were. The clear winners were upfront, 0.5,1,1.5 and 0.2,1,2. Based on this bench test, I have stuck with a 0.5,1,1.5 day staggered nutrient timing for session meads.

A couple of things to note. First, this is S-04, which is one of the few yeasts I know that can handle all the nutrients up front. Do not try to add all nutrients up front for other yeasts. S-04 is also prone to phenolics whereas other yeasts, like US-O5, are maybe less so. I would really like to try this with organic nutrients and US-05.

Also, the nutrient level was quite high, with the YAN from Go-ferm providing an equal amount of nutrients. This is inconsistent with evidence from another experiment where S-04 presented better with a low-level of compared to a high level of nutrients. I would like to try this with and without Go-ferm and with a low nutrient level.

Conclusion: stagger, it’s safer, and wait at least 6-12 hours to avoid unrecoverable nutrient burn. Get those nutrients in before 1/3 sugar break.

Kieselsol and Chitosan in a Traditional Mead

In this experiment, the use of a common two stage clarifying agents, Kieselol and Chitosan, is tested for its flavor and aroma contributions in a 4.5% ABV, carbonated, dry traditional mead fermented using S-04. The mead was fermented in one batch, then split between two identical secondary vessels and one was given the clarifying treatment. Other than the clarifying treatment, all other variables were identical. Triangle tests are conducted to see if participants can correctly identify the difference between the two meads. Respondents also provided feedback on the differences perceived in the two meads.

This is a sister experiment to the Kieselol and Chitosan in fruit mead. In that experiment, the use of the fining agent resulted in a significant deterioration in the flavor and aroma. However, that mead contained fruit, whereas this experiment is done on a traditional mead. Moreover, while the fruit mead was also relatively clear before adding the clarifier, the treatment for this traditional mead experiment was added directly after racking into secondary and the mead was still very hazy.

I wanted to do this test because I had observed the effect of fining agent on my meads. I made the same strawberry rhubarb mead a couple of times in the last year. Each time I added the fining agent, I noticed a major reduction in flavor and subsequently stopped using it. I wanted to do the test to see if it really did make a difference.

Kieselsol and Chitosan works really, really well at clarifying meads. It can even be added right at the end of primary when the mead is all hazy and full of gunk, and will drop the mead clear in little time, allowing for clear mead in secondary with very little lees. It is also been stated that fining agents “improve the color, odor, flavor, stability and mouthfeel of the finished product – along with many additional, subtle, benefits.” However, despite all these potential advantages, are we losing anything other than unwanted particulates when using Kieselsol and Chitosan?

In an article in the Critical Reviews in Food Science and Nutrition, Marín et al (2020) provides a literature review pertaining to the use of Kieselsol and Chitosan in wine. The studies surveyed analyzed the chemical composition of the wines after treatment. Regarding white wines, researchers have found significant loss in flavanols, medium-chain fatty acid ethyl esters, and terpenes (such as rose-oxide, linalool, citronellol, and geraniol) at common dosage rates. Moreover, Milheiro et al. (2017) find reduction of volatile phenols in headspace.

Chitosan has also been documented to reduce both tartaric and malic acids. Due to white wine’s lower phenolic levels, removal rates are higher than red wines, reaching as high as 30% and 20% for certain acids and flavanols. Treatment removes acids by acting as a polycation; binding anions from organic acids (Bornet and Teissedre, 2007). In at least three studies, decreases in titratable acidity or increases in pH were documented due to the significant removal of tartaric and malic acids (Castro-Marin et al., 2018; Quintela et al. 2012; Colangelo et al. 2018).

Finally, there is mixed evidence on showing that Kieselsol and Chitosan may result in perception of astringency, even at low levels (again, see Marín et al (2020) for a complete review). These findings all suggest potential effects on flavor – not as neutral as commonly assumed. Moreover, the conclusion of Marín et al (2020)’s literature review study was that despite notable effects in chemical composition, there has not yet been any sensory analysis studies to date on the effect of Chitosan treatment in wines. Hence, to the best of my knowledge, this is the first sensory evaluation study of the treatment effect on traditional meads (let alone wines).

My hypothesis was that treatment would reduce flavor and acid levels. This is based on evidence summarized in Marín et al (2020) and found in the experiment on the effects of Kieselol and Chitosan in fruit mead. However, I also expected the effect to be less noticeable compared to the fruit mead, since there may be fewer compounds to drop out in a traditional mead.

Recipe: 4.5%, Dry Traditional Short Mead, Nov. 2020, 16.5 liters

  • OG = 1.034
  • 1 liter of 2020 dark, last harvest, wildflower Honey from Nith Valley apiaries
  • 0.5 kg of creamed, organic, raw, Peace River honey
  • 15 liter spring water
  • 7 gallon Fermonster fermentor
  • 1.5 grams of calcium chloride
  • 0.5 grams of Himalayan sea salt
  • 11.5 gram packet of S-04
  • 0.5 grams of ascorbic acid
  • 1 gram of malic acid

Treatment:

  • Chitosan 1% at 8.3ml per gallon (2.18 ml/grams per liter)
  • Kieselsol at 2.5ml per gallon (0.66 ml/grams per liter)

Nith Valley late season darker honey tasting notes:

  • Low floral
  • Low perceived sweetness, not overtly honey like
  • Muddled caramel, minerality
  • Low acid
  • Low mixed herbal/woody, some foamed milk (alfalfa)

Nutrients (calculated using The MeadMakr BatchBuildr):

  • Recommended nutrient level is 78 ppm YAN for medium level
  • Actual: 73 ppm YAN (medium level, scaled up due to high pitch rate)
    • Fermaid-K: 2.3 grams (contibuted 13 ppm YAN)
    • DAP: 4.3 grams (contibuted 60 ppm YAN)

At pitch

  • Mixed honey, water, salts.
  • Sprinkled yeast on top of must

Fermentation Notes

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

  • +time 0, Mixed honey, water salts. Sprinkled yeast on must. Must is 64.6°F, pH 7.0.
  • +2 hours, fed all nutrients upfront with 2.3g of Fermaid-k and 4.3 g of DAP.
  • +1 days, active fermentation, 66.6°F
  • +2 days, degassed. Smells like apples. 66.1°F
  • +3 days, degassed, 66.5°F , 1.012
  • +4 days, 66.2°F , 1.002, smells of pear, apple.
  • +5 days, 65.6°F, fermentation slowing, smells like honey, apple. 1.000
  • +7 days, 65.6°F, FG 1.000. Racked into secondary. Added ascorbic acid and malic acid.

Secondary

  • Added 1st stage clarifier to one jug immediately, then swirled gently
  • +2 hours later added 2nd stage to one jug, swirled gently
  • The next day, treated mead dropped clear.
  • Bottled after another week to 2.5 volumes (primed with honey).

The untreated meads was still slightly hazy when bottling. The treated mead was clear.

Water profile 

The mineral profile of the spring water, contribution of the salt additions and the final water profile was as follows.

Initial Tasting Notes

At bottling, I was a bit disappointed with the character of the mead. They had a mild lager-like aroma. There was some nice apples esters and fermented honey character, but they were slightly muddled by the slight sulfur. I attribute this to not using Go-ferm, and just replying on aerating with a wine whip instead of by shaking or using pure 02. That said, the mead was intentionally fermented this way in a side-by-side with an identical batch using EC1118 (forthcoming, but as a preview, the EC1118 batch was much worse). I debated whether to continue with the experiment, but thought that it might be interesting to see the effect in the presence of an off-flavor.

Triangle Tests 

Due to Covid-19, and in consultation with statisticians, every participant was sent two bottles and completed up to five triangle tests. Participants were sent four or five experiments and knew that I was testing something around nutrient regimes, clarifying agents, and acidity levels. The bottles were labeled experiment A, B, C etc as well as being labeled as treatment or baseline. Every participant was also sent enough identical red solo cups.

One scoresheet was filled out by each participant for each experiment. Participants were asked their experience level with meads, how blown their palate was, and their status as judges and home/professional brewers. Experience was given a value from one to five where one is first time having a mead to five being well-experienced. Palate was given a value from one to five where one is having had nothing to drink yet, and five was that they’ve already had too much (like just drank an IPA and sitting in a brewery). Participants were asked to say which mead they preferred and just select one if they couldn’t tell the difference.

There were 6 participants, each completed five triangle tests, so there were 30 triangle tests completed overall. We had a good selection of mead experts and mead enthusiasts. There were two BJCP certified beer judges and two BJCP mead judges.

On average, people were experienced with meads and their palate was not tired. All had some experience with meads and off flavors. Basic summary statistics on the self reporting of participants experience and palate when taking the triangle tests:

All responses were collected when the meads were 6-8 months old.

Results

There was a significant difference between the two meads. In 19 of the 30 triangle tests, participants could identify the odd mead out! The null that the results were from random guessing is rejected with 99.99 percent confidence. However, participants were split on the mead that they preferred. The null hypothesis of equal preference between the meads is unable to be rejected. Here is a summary of the results:

My wife and I did five triangle tests and each got three right, mine the last three once I noted the difference in acid levels and hers the first three. One person got all five triangle tests wrong, two got all five triangle test correct. While participant fixed effects were significant, no time fixed effects were significant. Most participants commented that the meads could be distinguished from each other relatively easily, where others said it was difficult. What people described as the difference between the two meads is summarized in the table below. Note, the participant who got all five wrong, did not provide tasting notes. The participants and the percent of correct answers is shown in the table.

In general, the tasting notes are more varied than the experiment on the effects of Kieselol and Chitosan in fruit mead. The baseline mead was described by three participants as being more acidic, whereas the mead with the treatment was only described as being more acidic by one participant. In contrast, one participant described the treatment mead as being bitter, whereas another described baseline as dryer. The treated mead was described as having better balance by three participants, all of whom preferred the treated mead.

Regarding aroma and flavor intensity, two participants noted that the mead without treatment had more aroma and flavor, and another participant said it had more honey aroma. This contrasts with only one participant that said the treatment had more honey flavor.

Note that the one participant who got all five triangle tests wrong did not provide a preference at the time of submitting feedback and when asked to pick, randomly picked baseline. Moreover, the first participant was relatively split on the preference, but did settle on the baseline because they preferred the higher acid and intensity of the aroma and flavor. Even in the most generous case, three preferred the treatment, one only mildly preferred the baseline, and the other preferred the baseline.

It’s hard to make head and tails from the tasting notes. My interpretation, based on my triangle tests, was that the acidity of the baseline mead was perceived to be too high by some participants due to the added malic acid (0.25 grams per gallon). This is consistent with the three comments on better balance for the treated mead. In contrast, the two participants who liked the baseline mead commented that they liked the higher acidity level. Moreover, the treated mead had notable lower aroma and flavor. As the aroma was a combination of the lager-like character and the floral/honey intensity, those who didn’t like the lager-like character might have preferred the mead with suppression of both characteristics.

Conclusion

One of the most interesting outcomes of the experiment is that the meads were significantly different. Thus, treatment with Kieselsol and Chitosan is again shown in sensory analysis to not be neutral. This aligns with the scientific evidence on the reduction of acidity and flavor compounds when treating with Chitosan.

Relative to the experiment on Kieselol and Chitosan in fruit mead, the traditional mead had more particulates when the fining agent was added. For the fruit mead, a perception of bitterness was noted in the treated mead, that was not as commonly mentioned in this experiment. I do wonder if these are related. Perhaps, a hazy mead is needed for all the Chitosan to drop out and not leave any bitterness? More testing is needed.

Finally, I have successfully used the fact that Kieselsol and Chitosan can drop acid out of a mead. After this experiment was completed, I made a mojito mead. However, either the limes were much more acidic or had much more juice than the previous times I made the mead because the acidity ended up being too high. I was able to fix this by treating with Kieselsol and Chitosan and racking off the original keg. Then I added more mint to bring back the aroma, and voilà, it fixed the high acidity.

In the past, I recommended the two stage clarifier be used at the end of primary to speed the turn around time, for example for the Short Mead Recipes. Now, this comes with a caution of lower flavor, aroma, and acidity.

References

Bornet, A., & Teissedre, P. L. (2008). Chitosan, chitin-glucan and chitin effects on minerals (iron, lead, cadmium) and organic (ochratoxin A) contaminants in wines. European Food Research and Technology226(4), 681-689.

Castro-Marín, A., Buglia, A. G., Riponi, C., & Chinnici, F. (2018). Volatile and fixed composition of sulphite-free white wines obtained after fermentation in the presence of chitosan. LWT93, 174-180.

Castro Marín, A., Colangelo, D., Lambri, M., Riponi, C., & Chinnici, F. (2020). Relevance and perspectives of the use of chitosan in winemaking: a review. Critical Reviews in Food Science and Nutrition, 1-15.

Colangelo, D., Torchio, F., De Faveri, D. M., & Lambri, M. (2018). The use of chitosan as alternative to bentonite for wine fining: Effects on heat-stability, proteins, organic acids, colour, and volatile compounds in an aromatic white wine. Food chemistry264, 301-309.

Milheiro, J., Filipe-Ribeiro, L., Cosme, F., & Nunes, F. M. (2017). A simple, cheap and reliable method for control of 4-ethylphenol and 4-ethylguaiacol in red wines. Screening of fining agents for reducing volatile phenols levels in red wines. Journal of Chromatography B1041, 183-190.

Quintela, S., Villarán, M. C., De Armentia, I. L., & Elejalde, E. (2012). Ochratoxin A removal from red wine by several oenological fining agents: bentonite, egg albumin, allergen-free adsorbents, chitin and chitosan. Food Additives & Contaminants: Part A29(7), 1168-1174.

Peer Reviews:

The methodology comments from the referees in the high versus low nutrient level experiment also pertain to the method used for this article. This includes: 1) Justin Angevaare, PhD, Statistician, author of p-value calculator and award-winning homebrewerhttps://onbrewing.comand 2) Chris Kwietniowski, award-winning home brewer, participant. 

Peer Review 1: Justin Angevaare, PhD, Statistician, author of p-value calculator and award-winning homebrewerhttps://onbrewing.com

Not so much at the crux of this experiment, but did the participants pick up on the lager-like character you mentioned at all? I see you felt aroma – including this lager-like character – was lower in intensity in the treated mead.

  • Response: Thank you for making me go and double check. Yes, one participant mentioned it was more like a beer in balance. I lengthened the tasting notes to copy over everything that was written.

Can you be anymore specific on the sulfur you mention? Like low H2S?

  • No really. There was no rotten egg or matches, just tasted like a bud-light.

How do I read the tasting notes table? At first I thought it was 1 participant per line, but you had 6 participants listed and 7 tasting notes.

  • Response: The table has been updated to show the participant and the number of times each participant got it correct. This is much easier to read, and thank you for prompting this.

Peer Review 2: Tom Repas, Master Beekeeper, owner of Canyon Rim Honey BeesAMMA MeadCon speaker, award winning mead maker.

Did you notice a chnage in the pH after treatement?

  • Response: No, unfortunately, I did not test this. I did not realize this would be a concern until after the experiment and read the literature more carefully. This is fascinating, and I wish I did. I will replicate this in a separate mead and report back.

Peer Review 3: William R. Otte, Homebrewer

I don’t think you’re really giving the fining agents a fair break. In my opinion your dosing of kieselsol and chitosan are hilariously high for a 4.5% hydromel. I believe that 8.3ml/gal for Chitosan and 2.5ml/gal for Kieselsol are basically the dosing of the DualFine/SuperKleer product.

You gotta remember a couple things about that dosing:

  1. Fining agents sold to home brewers are dosed so they work the first time, every time.  As such, their dosing is almost always at the maximum recommended dosing, and sometimes even beyond dosing rates recommended in commercial winemaking.
  2. DualFine/Superkleer are mainly marketed at winemakers, which will almost always be at 12-14% with high fruit loads, and as such will almost always have way more turbidity than a 4.5% hydromel.

Not all mead/wines are the same, and each will have a different need when it comes to fining agents. If you look at the technical data sheet for any fining product sold for commercial winemaking, every single one will have a dosing range and in bold letters that it is critical to conduct fining trials before doing fining agents to determine the minimum dosing that meets your clarifying needs. Your experiment demonstrates why that is.

More reasonable dosing ranges in my opinion would be 5.5ml-7.5ml/gal for 1% Chitosan, and 1-2ml/gal for 30% Kieselsol.

I would say that the conclusions of your article are not so much that Kieselsol and Chitosan have a noticeable impact on flavor, aroma, or mouthfeel; it is more that blindly throwing a fining agent of any kind at your mead or wine without a bench trial can have a noticeable impact on flavor, aroma, or mouthfeel.

I think an interesting follow up to your experiment would be to do the same thing, except conduct a bench trial to determine the minimum dosing needed to clear the mead. I find that the minimum dosing in the ranges I recommended is almost always more than sufficient to clear 12-14% traditional meads. I’d imagine a 4.5% hydromel could use less.

  • Response: I agree that lower dosing may be desirable, especially for short meads. In fact, after further investigation, the dosing rate Kieselsol recommended by Wine Maker Magazine, for example, is 1 to 2 ml per gallon. The fact that 2.5ml/gal is provided by DualFine/SuperKleer type products means they are providing more than the recommended maximum amount for home brewers in their products. It would be fascinating to do a bench trial to find appropriate levels for different types and strengths of mead. Since for home brewers, bench trials may not be possible, it may be prudent to only add half, the amount given and only add more if needed. I’ll try some bench trials for some session mead recipes.
  • However, while I agree with your main point of not blindly throwing in products, studies have shown that the product does remove aroma, flavor and acid. Maybe they are not removed if used in lower doses (like the effect on color) but it is also possible that the taste threshold is just too low as to not detect it. This threshold may differ for the effects on acids or taste/aroma. This would be an interesting outcome of more bench trials and triangle tests.  

Kieselsol and Chitosan in Fruit Meads

The haze craze is off to the races in juicy IPAs, but the opposite is still true for meads. A crystal clear mead can be the difference between a medal and a flop at competitions. A wide range of fining agents are in the arsenal of a mead maker. Most fining agents work by attracting positively or negatively charged particulates suspended within the mead. This causes suspended particles to precipitate to the bottom of the vessel. A common practice is to use a positively charged agent, such as gelatin or Chitosan, followed by a negatively charged agent, primarily Kieselsol. The treatment will bind with proteins, yeast, polyphenols and other negatively-charged particles, and is especially effective. Chitosan has the advantage that it does not require tannins to work properly, allowing its use in meads, white wines, ciders, etc. Most home brew and wine making stores sell Kieselsol and Chitosan together, sometimes under the brand name Super Kleer.

Kieselsol and Chitosan works really, really well at clarifying meads. It can even be added right at the end of primary when the mead is all hazy and full of gunk, and will drop the mead clear in little time, allowing for clear mead in secondary with very little lees. It is also been stated that fining agents “improve the color, odor, flavor, stability and mouthfeel of the finished product – along with many additional, subtle, benefits.” However, despite all the advantages, are we losing anything other than unwanted particulates when using Kieselsol and Chitosan?

It is common to find comments, for example from my local home brew store, that Kieselsol is not recommended for red wines as it can strip color. Moreover, within mead making circles, the use of some fining agents such as gelatin have been commented to strip tannin. However, it is unclear, at least to me, if Kieselsol and Chitosan does the same. See an excellent GotMead podcast with Tom Repas for information on use of fining agents in secondary and the ability of gelatin to strip tannin. However, there is little hard evidence on adding Kieselsol and Chitosan in meads.

Interestingly, the common advice on Kieselsol and Chitosan seems at odds with the current literature on wines. A recent article in the Critical Reviews in Food Science and Nutrition provides a literature review when pertaining to wine. In summary, researchers have found that red wine color loss is only found at dosing rates that are four or more times higher than the maximum dosing rates used by home brewers. Thus, the risk to color loss may be overblown. However, researchers have found that there are significant loss in flavanols, medium-chain fatty acid ethyl esters, and terpenes in both red and white wines at common dosage rates. Moreover, Kieselsol and Chitosan have been documented to reduce both tartaric and malic acids. Finally, there is emerging evidence that Kieselsol and Chitosan may result in perception of astringency, even at low levels. These findings all suggest potential effects on flavor. Maybe this fining agent is not as neutral as commonly assumed?

Are we losing anything else in our path to clarity? Clearly, this needs to be clarified. 

In this experiment, the use of a common two stage clarifying agents, Kieselol and Chitosan, is tested for its flavor and aroma contributions in a 4.5% ABV, carbonated, dry cream soda mead fermented using D-47. The mead was fermented in one batch, then split between two identical secondary vessels and one was given the clarifying treatment. Other than the clarifying treatment, all other variables were identical, and the batches were from the same ferment. Triangle tests are conducted to see if participants can correctly identify the difference between the two meads. Respondents also provided feedback on the differences perceived in the two meads.

My hypothesis was that the treatment may remove mouthfeel due to the reduction in particulates, but at the low dosage would not affect color. I had some suspicion that it would affect aroma/taste.

Recipe: 4.5%, Dry, Cream Soda Mead, Nov. 2020, 15 liters

  • OG = 1.034
  • 1 liter of 2020 golden wildflower Honey from Nith Valley apiaries
  • 0.5 kg of creamed, organic, raw, Peace River honey
  • 15 liter spring water
  • 7 gallon fermonster fermentor
  • 1.5 grams of calcium chloride
  • 0.5 grams of gypsum
  • 0.5 grams of Himalayan sea salt
  • 10 grams of D-47
  • 2 grams of ascorbic acid
  • 3 grams of citric acid

Treatment:

  • Chitosan 1% at 8.3ml per gallon (2.18 ml/grams per liter)
  • Kieselsol at 2.5ml per gallon (0.66 ml/grams per liter)

Nith Valley honey tasting notes:

  • Moderate floral
  • High perceived sweetness,
  • Honey comb, honey like, bees wax
  • Citrus

Nutrients (calculated using The MeadMakr BatchBuildr):

  • Low nutrient profile recommends 65.2 ppm YAN
  • Actual: 82 ppm YAN (medium level, scaled up due to high pitch rate)
    • Fermaid-K: 2 grams (contributed 13 ppm YAN)
    • DAP: 5 grams (contributed 69 ppm YAN)

At pitch

  • Mixed honey, water, salts.
  • Shook jug for two minutes to aerate
  • Sprinkled yeast on top of must

Fermentation Notes

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

  • +time 0, Mixed honey, water salts. Sprinkled yeast on must. Must is 62-63°F. Swirled after 1 minute.
  • +1 hour, fed with 1g of Fermaid-k and 2 g of DAP.
  • +1 day, fed with 1g of Fermaid-k and 2g of DAP. 64°F
  • +2 days, degassed. Fed with 1g of DAP. 64°F. 1.024
  • +3 days, degassed, 64°F , 1.012
  • +4 days, degassed, 64°F , 1.002, added ~2 kg of polish sour cherries in a mesh bag warmed to 65°F
  • +5 days, removed fruit, hardly any color left in fruit mush. 1.000
  • +7 days, racked into 2 x 8 liter jugs. Added half a vanilla bean split down the center, 1 gram of ascorbic acid, and 1.5 grams of citric acid to each vessel. Mead dropped relatively clear quickly.

Secondary

  • After two weeks, added 1st stage clarifier to one jug then swirled gently
  • 24 hours later added 2nd stage after 24 hours to one jug, swirled gently
  • Bottled after another week to 2.5 volumes (65 grams of honey).

The meads were both pretty clear before bottling. It was not possible to tell which was more clear in secondary.

Water profile 

The mineral profile of the spring water, contribution of the salt additions and the final water profile was as follows.

Initial Tasting Notes

At two months old, I tasted both meads, and they seemed different. The baseline mead was really nice. It had bright fresh cherry flavor and mild vanilla. I would have liked more vanilla intensity to make it taste like a cream soda and less of a cherry mead. The fermentation was clean and had little fermentation characteristics apart from some mild malt-like yeast character. However, the mead with the clarifying treatment was slightly bitter and less well carbonated. I figure the low carbonation was due to less residual yeast in suspension. I let them sit for a while so that they both fully carbonated.

Triangle Tests 

Due to Covid-19, and in consultation with statisticians, every participant was sent two bottles and completed up to five triangle tests. Participants were sent four or five experiments and knew that I was testing something around nutrient regimes, clarifying agents, and acidity levels. The bottles were labeled experiment A, B, C etc. as well as being labeled as treatment or baseline. Every participant was also sent enough identical red solo cups.

One scoresheet was filled out by each participant for each experiment. Participants were asked their experience level with meads, how blown their palate was, and their status as judges and home/professional brewers. Experience was given a value from one to five where one is first time having a mead to five being well-experienced. Palate was given a value from one to five where one is having had nothing to drink yet, and five was that they’ve already had too much (like just drank an IPA and sitting in a brewery). Participants were asked to say which mead they preferred, and just select one if they couldn’t tell the difference.

There were 6 participants, each completed five triangle tests, so there were 30 triangle tests completed overall. We had a good selection of mead experts and mead enthusiasts. There were two BJCP certified beer judges and two BJCP mead judges.

On average, people were experienced with meads and their palate was not tired. All had some experience with meads and off flavors. Basic summary statistics on the self reporting of participants experience and palate when taking the triangle tests:

All responses were collected within the same month. Tests were evaluated when the meads were 6-8 months old.

Results

There was a significant difference between the two meads. Out of the 30 triangle tests, 20 could identify the odd mead out! The null hypothesis that the results were from random guessing is rejected with near 100 percent confidence. Moreover, all participants preferred the mead that was not clarified. The null hypothesis of equal preference between the meads is rejected with 96.8 percent confidence. Here is a summary of the results:

I did five triangle tests and got the first two wrong. It wasn’t until I noticed the flavor intensity that I got the remaining correct. Another participant got the first few correct, and the remaining incorrect. Most other participants’ incorrect responses were seemingly random, and no time fixed effects were significant. Some participants commented that the meads could be distinguished from each other relatively easily.

What people described as the difference between the two meads is summarized below. The mead that did not have the clarifier was described as more vibrant, fruitier, and better balanced. In contrast, two participants described the clarified mead as being bitter and another described the perception as astringent. That is fascinating, as astringency was noted to occur in some previous wine studies. Moreover, three participants noted muted flavor, blander and being more watery. One participant commented that they thought the treatment was additional fruit added. Thus, there does seem to be perceived differences in the level of flavor and aroma, which is consistent with some previous studies. Surprisingly, the findings align with results in the abovementioned scientific studies, and there was quite a bit of consistency in feedback across participants.

Conclusion

I was really surprised by how different the two meads were. I often use Kieselol and Chitosan for a quick turn around time in short meads. Likewise, I also use it in relatively clear standard meads to make sure there is no dust of yeast in the bottom of bottles over time for competitions. It always does the job of clarifying.

Now, I have more clarity that mead clarity using Kieselol and Chitosan may not be worth the price. The loss of fruit character was significant. Astringent and bitterness was added. It’s also interesting, that the often cited reduction in color intensity was absent. However, this is all consistent with some recent studies for wine.

A couple of things to note. The meads where relatively clear when I added the clarifier. I would not usually add the clarifier for such a mead if it’s for my own personal use. However, I would use it for a standard strength mead to avoid yeast dust. It would be interesting to repeat the experiment for a standard strength mead. I also use the clarifier at the end of primary since it can knock the mead clear. I wonder if the impact would be similar for a treatment at the end of primary for a much hazier mead, as there maybe more positively charged particulates to help any residual Kieselol to drop out. More testing is still needed for this. Perhaps a bench trial to see what the threshold is.

The same treatment in a traditional mead was evaluated at the same time (forthcoming). Interestingly, participants were able to detect a significant difference; however, preference was split. This may suggest that the issues may pertain to fruit meads, although it could also be due to the fact the there were more particulates in the traditional mead. 

In the past, I recommended the two stage clarifier be used at the end of primary in a really hazy mead to speed the turn around time, for example for the Short Mead Recipes. Now, this comes with a caution for relatively clear fruit meads. 

Peer Reviews:

The comments on methods from the referees in the high versus low nutrient level experiment also pertain to the method used for this article. This includes: 1) Justin Angevaare, PhD, Statistician, author of p-value calculator and award winning homebrewerhttps://onbrewing.comand 2) Chris Kwietniowski, home brewer, participant. 

Additional peer reviews to follow.

Peer Review 1: Tom Repas, Master Beekeeper, owner of Canyon Rim Honey Bees, AMMA MeadCon speaker, award winning mead maker.

Excellent write up! Interesting results!

  • Responce: Thanks Tom. I have greatly benifited from your service to the mead community. Thanks for everything you have shared with other mead makers.

Oh and if I said a fining agent had potential for removing tannins that would’ve been gelatin (not Kieselsol or Chitosan). If I said something different on that podcast then I must have misspoken.

  • Responce: Oops. A previous version of this article had incorrectly stated “… in a recent GotMead podcast, Tom Repas commented that this clarifier should be used with caution as it can strip tannin but can also be used to strip excess tannin.” This has been corrected. I recommend anyone to check out this podcast as it is a wealth of information.

Peer Review 2: Ryan Dunlop, PhD, BJCP certified, award willing homebrewer, and statistics wizz.

…. shouldn’t the preference test be two sided?

For the “can we tell them apart?” question, one sided makes sense because you don’t care if you choose wrong more often than random chance. With a good design, you know that that is still random chance.

If either could be better than the other, I think two sided is better because you have two ways you can “have one more preferred than the other”. Otherwise you are kind of assuming that you know one is preferred and if the data show the opposite it’s just random chance. 

  • Responce: I agree. Previously, a one-sided test was used to test the preference of one mead over the other. However, since the direction of the preference cannot be known a priori, this has been changed to a two-sided test. Also, thanks to Justin Angevaare for confirming the test should be two-sided.

Ale Yeast: High vs Low Inorganic Nutrients

Much more information is available on wine yeast than ale yeasts. While a mead maker can consult the Winemaking Handbook from Scott Labs to look up the nutrient requirement of most used wine yeasts, no similar bible exists for ale yeasts. I have personally contacted three ale yeast manufacturers, and they said that nutrient requirement information was not available for their ale yeasts. One example of the lack of data is the little-noticed but big change between TOSNA 2.0 and TOSNA 3.0, that reduced the recommended level of nutrients for ale yeast from high to low. Moreover, with the range of levels for wine yeasts its unfortunate that all ale yeasts get clumped together, an English ale yeast may have different nutrient requirements than a Kviek yeast in nutrient calculators. As nutrients are a major determinate of proper mead fermentation, mead makers really need more data for ale yeasts.

In this experiment, a high versus low nutrient rate is tested for its flavor and aroma contributions in a 4.5% ABV, carbonated, dry traditional mead fermented using an English ale yeast, Safale S-04. The ale yeast strain, S-04 is noted to have a clean flavor, contributing apple esters, and has a fast fermentation with good flocculation. Other than the nutrient level, all other variables were identical, and the batches were fermented side by side. Triangle tests are conducted to see if participants can correctly identify the difference between the two meads. Respondents also provided feedback on the differences perceived in the two meads.

My hypothesis was that it may affect the ester levels, but given my prior success using medium and high levels of nutrients, I thought that a low level of nutrients could cause a sluggish fermentation and could also have potential off flavors.

Recipe: 4.5%, Dry Traditional Short Mead, January 2021, 1 gallon

  • OG = 1.034
  • 0.33 liters of 2020 golden wildflower Honey from Nith Valley apiaries
  • 4 liter water spring water in 8 liter jug
  • 0.35 grams of calcium chloride
  • 0.2 grams of potassium bicarbonate
  • 0.12 grams of Himalayan sea salt
  • 1.5 grams of Safale S-04

Honey tasting notes:

  • Moderate floral
  • High perceived sweetness,
  • honey comb, honey like, bees wax
  • Citrus

Nutrients (calculated using The MeadMakr BatchBuildr):

  • Low nutrient requirement: 65.2 ppm YAN
    • Fermaid-K: 0.5 grams
    • DAP: 1 grams
  • High nutrient requirement: 108.7 ppm YAN
    • Fermaid-K: 0.9 grams
    • DAP: 1.7 grams

At pitch

  • Mixed honey, water, salts.
  • Shook jug for two minutes to aerate
  • Sprinkled yeast on top of must

Fermentation

  • Degassed by swirling the jug every 12 hours for the first two weeks.
  • +2 hours, first 1/3 nutrient addition. 64.3°F
  • +24 hours, second 1/3 nutrient addition. 65°F
  • +48 hours, third 1/3 nutrient addition. 65°F

Fermentation Notes

Regular temperature, pH, gravity and aroma tests were taken. The table below summarizes the observations.

Time/ Temp.HighLow
+0 hours  63°FpH 7,
SG 1.035
pH 7
SG 1.035
+20 hours 67.6°FHoney/ fermentaion/ yeast  Raw honey / light fermentation
+36 hours 66.9°FSome ferm stress/ light rubber, 1.026Raw honey / clean, 1.028
+3 days 66.6°FClean/ light esters, 1.012 Clean, honey, 1.014
+4 days 64°Ffruity esters, 1.006Raw honey, 1.014
+5 days 66.6°Ffruity esters/ clean, 1.004Clean/ honey, 1.012
+6 days 66.6°FClean/ floral/ light pomme esters. No heat/ smooth, 1.000
Transferred to secondary
Light esters/ honey, 1.008
+7 days 66.6°F Great/ honey/ some esters, 1.006
+9 days 66.6°F Hight raw honey clean, low pomme esters, 1.004
+13 days 66.6°F clean, light honey, low/no esters, 1.000
Transferred to secondary

Basically, the fermentation with the low nutrients took twice as long to ferment. Throughout the fermentation, the low nutrient regime smelled more like honey, whereas the high levels of nutrients has more pear and apple esters.

Secondary

  • Cold crashed at 58°F for 2 weeks.
  • Bottled after one month to 2.5 volumes.

Water profile 

The mineral profile of the spring water, contribution of the salt additions and the final water profile was as follows.

Initial Tasting Notes

At bottling, I tasted both meads and they both seemed different but were both excellent. The mead with the low nutrient levels had mild diacytal/butterscotch and some sulfur. However, it was sweeter, and had more raw honey, and minerality. In contrast, the high nutrient level was all apple and pear ester character. The high level nutrient mead also had more noticeable alcohol, was dryer, and tasted like fermented honey rather than raw honey.

Triangle Tests 

Due to Covid-19, and in consultation with statisticians, every participant was sent two bottles and completed up to five triangle tests. Participants were sent four or five experiments and knew that I was testing something around nutrient regimes, clarifying agents, and acidity levels. The bottles were labeled experiment A, B, C etc as well as being labeled as treatment or baseline. Every participant was also sent enough identical red solo cups.

One scoresheet was filled out by each participant for each experiment. Participants were asked their experience level with meads, how blown their palate was, and their status as judges and home/professional brewers. Experience was given a value from one to five where one is first time having a mead to five being well-experienced. Palate was given a value from one to five where one is having had nothing to drink yet, and five was that they’ve already had too much (like just drank an IPA and sitting in a brewery). Participants were asked to say which mead they preferred and just select one if they couldn’t tell the difference.

There were 6 participants and 26 triangle tests were completed overall. We had a good selection of mead experts and mead enthusiasts. There were two BJCP certified beer judges and two BJCP mead judges.

On average, people were experienced with meads and their palate was not tired. All had some experience with meads and off flavors. Basic summary statistics on the self reporting of participants experience and palate when taking the triangle tests:

All responses were collected within the same month. Tests were evaluated when the meads were 4-5 months.

Results

There was a significant difference between the two meads. Out of the 26 triangle tests 24 could identify the odd mead out! A test that the results were from random guessing is rejected with near 100 percent confidence. Moreover, all participants preferred the low nutrient rates. The null hypothesis of equal preference between the meads is rejected with 96.8 percent confidence. Here is a summary of the results.

I did three triangle tests and found them effortless. Participants commented that it could be done by aroma alone.

What people described as the difference between the two meads is summarized below. The high nutrient level mead was described less pleasantly, with alcohol and off flavors described. In contrast, the low nutrient as being more honey like and was smoother. I was surprised at the results, as my tasting at bottling was quite different.

Conclusion

I was really surprised by how different the two meads were. When I began making mead, I often used high level of nutrients with ale yeasts because that was what was recommended. Now, there is clear evidence that for me that when staggering with inorganic nutrients it’s better to go low. It’s also interesting that despite all the focus on quickly turning around meads, it is clear that you can lose out from too aggressive of a fermentation. Is it worth taking half the time in fermentation if the product is half as good?

I focused this test on inorganic nutrient because I want people who do not have access to Go-ferm and Fermaid-O to still be able to make great mead. That said, the use of Go-ferm and some organic nutrient may have further benefited the meads, especially for the first nutrient addition. More testing is still needed for this.

Moreover, I have done bench trials on the timing of the nutrient additions for short meads since this experiment. The timing of the nutrient additions was quick and could have benefited from staggered out more. As summarized in the metadata of Short Mead Recipes, S-04 is particularly susceptible to nutrient burn from staggering with inorganic nutrients when done within the first 24 hours. The yeast is one of the few I know that can handle all the nutrients up front. I plan to replicate this experiment but with a better staggering regime and compare a low and medium level of nutrients. It would also be interesting to compare all nutrients upfront versus stagger when using S-04.

I still use a medium to medium-low nutrient level when staggering inorganic nutrients in short meads with S-04 as I do like the extra apple esters that results. Of course, it is also needed to test nutrient levels for different ale yeast, including Kveik and US-05. What is clear is that when it comes to ale yeasts, there is still much to learn.

Peer Review 1: Justin Angevaare, PhD, Statistician, author of p-value calculator and award winning homebrewerhttps://onbrewing.com

Is each triangle test considered an independent observation here, or is some kind of trial-dependence built in to your analysis?

  • Response: Yes, every observation was considered independent.

Would it be helpful for consistency if the mead was decanted into a serving vessel first, and exact measured quantities added to the cups (cups on a scale while being filled perhaps?) I’m wondering if a bias in fill level could be picked up by participant due to having 7 of one to fill and 8 of the other (FWIW seems unlikely to me). Maybe they should fill 8 from both, and randomly select one to discard after having done so?

  • Response: Each participant was given a 12 oz bottle and told to pour 1 to 1 1/2 of an oz in each cup, with the expectation that they would pour the same amount in each cup. I doubt the participants poured less for the sample with 7 vs 8 cups, but it’s an excellent idea to just say 1 oz for each cup from now on and do 8 to avoid the potential for this.

Was the identification rate equal on the early trials vs. later trials? I can imagine some learning rate by the taster based on them learning results after each trial. I can also imagine certain volatile compounds that may help in identification may have flashed off by trial #5.

  • Response: The incorrect responses were given on trial 2 and 5. Yes, there could be a time fixed effect from learning or volatilization. I also suspect there could be palate fatigue. I suspect there are forces in each direction but given the low failure rate, I suspect controlling for it would not matter for this experiment. It would be interesting to test for this in an experiment that exhibited more trial time variation.

Are the temperatures listed fermentation chamber temps or mead temperatures? Can it be assumed the faster fermentation resulted in a higher temperature for that mead?

  • Response: Mead temperatures. I did not detect temperature variations across meads possibly due to the small volume.

Is phenol production characteristics of yeast generally a matter of gene promotion rather than gene presence/absence? Asking as I can’t remember having had a non-phenolic yeast produce perceptible phenol.

  • Response: No idea. S04 is phenolic prone and in experience more sensitive to phenolic production relative to say US-05.

Are any components of your nutrient regime phenol precursors/directly used by yeast in phenol production? (ferulic acid on my mind)

  • Response: The exact formula of Fermaid-k is not published, so I do not know. It would be interesting to replicate the experiment, but with different nutrient sources. I suspect the use of DAP, particularly when combined with staggering in the first 48 hours, was a major reason for the phenolics. It’s an interesting question though, maybe S04 does have higher nutrient requirements, but it’s just that S04 is sensitive to DAP levels or a certain range. This could explain the sluggish fermentation and off-flavors noted at bottling. Replication with other yeast and nutrient regimes could give us a better idea of this.

Side comment: Reading this reminds me of something I’ve run into repeatedly with sourdough cultures – feeding mine with high nutrient flours like rye or fresh whole wheat seems to result in increased vigour, but also more sulfur, solvent aroma, and less depth.

  • Response: Interesting. When people advocate for certain nutrients by showing better fer mention speeds, like in the case for Go-ferm in the Scott labs Handbook, I always wonder to myself: “yea but what does the difference taste like?”

Peer Review 2 Chris Kwietniowski, award winning home brewer, triangle test participant.

Being one of the tasters having done the 7 of this and 8 of that pouring myself, I think for certain people there may be an element of “counting cards” when you reach the last trio of samples. I certainly didn’t, but maybe someone reaches the end knowing which sample must be the one with 2? But in red solo cups with 1/8th of a bottle, the filling level is like 1/2″ to 1″ with sort of random inconsistencies.

  • Response: It was good to hear your experience and that this did not affect your triangle tests. It will be a good idea from now on to just ensure the instructions insist the pour is identical across cups and not give the 1 to 1 1/2 of an oz range. I will also ask for the order of the tests to be randomized or make sure that 8th cup gets added randomly.

And about the side comment on speed… I think the assumption is right that “faster is better” when comparing to a miserable, sluggish, or incomplete ferment. But at some point you can probably make gains in speed without improving the product.

  • Response: Agree, and the focus on fermention optimization needs to continue to find that sweet spot.

Lacto Soured Orange Blossom, 12 % ABV, bone-dry

This is one of my favorite meads of all time. It is based on the Lacto Soured Orange Blossom, 12% ABV, bone-dry, mead from Gold Coast Meads. Anytime I lacto sour a traditional, I think to myself that this is the way traditional were meant to be made. The brightness that comes from a co-ferment of a lacto sour enhances the aroma and body. Also, the brightness from the acidity results in high perceived sweetness for a dry mead.

Recipe for 5.25 liters:

  • WLP001 California Ale Yeast (I used second generation, wouldn’t now)
  • 1.25 liters (2.75 lbs) of 2017 orange blossom honey from Dutch Gold Honey.
  • 4 liters of spring water
  • 5 pills of 100 billion cell mixed probiotics

Specs:

Total Nutrients

  • 3.5 grams Fermaid-O (60 YAN)
  • 6.25 grams Go-ferm (155 YAN)
  • 1.5 grams Fermaid-K (30 YAN)
  • Total: 245 YAN

Fermentation:

  • T=0 – mixed, honey, water, 6.25 grams of Go-ferm, and probiotics, temperature ~ 68°F
  • +3 days – added 2 grams of Fermaid-O, pitched the yeast, swirled twice a day
  • +5 days- 1.5 grams of Fermaid-K, swirled twice a day
  • +6 days – slight sulfur so added 1.5 grams of Fermaid-O and 0.5 grams of Go-Ferm, swirled once a day for another week

After Fermentation:

  • +2 months. FG 0.996. Transferred to 1 gallon glass carboy, added 1 oz of orange blossom honey.
  • +4 months – bottled.

Impressions:

Looking back, I would not have formulated the nutrients this way. That said, it worked. The mead tasted excellent and was very bright. At two months I did notice some yeast/ Go-ferm flavor, which is why I added 1 oz of honey in when transferring, and the flavor seemed to be gone by four months. The Florida/Dutch Gold orange blossom honey character was strong, but not as fresh orange as the Cali blossom honey character of the one I tried from Gold Coast Meads. That said, it was delicious. I remember thinking that all traditional meads should be co-fermented with lacto.

I served this one to my friends, and they all loved it. They couldn’t believe it was bone-dry since it had a tonne of perceived sweetness. In fact, when one of my friends asked me to help him with a mead he wanted to make this mead. However, I never got to try it since he drank three gallons of it before it was even bottled!

I sent the mead to competitions. No-one, at least at the time, made sour mead in Canada and orange blossom is hard to come by. I got raving reviews from some judges. The other judges said the perception of sweetness was too high when I had claimed it was a dry mead and docked me points… come on!!

Evaluations:

M1C: Sweet Orange Blossom Traditional

I make mostly dry or semi-sweet meads for myself, but make semi-sweet or sweet meads for competition. This is the sweetest traditional mead I had made to date, and it won me a few gold medals and at least one mead-maker of the year.

This recipe came from Ken Shramm on some podcast. I went back and listed to a bunch of them but can’t seem to find which one. Let me know if you know which podcast he talked about rehydration and adding a vanilla bean to a traditional orange blossom that finishes at 1.05 gravity. It is Ken Shramm super sweet but phenomenal after some aging.

Recipe:

  • 10 g 71B yeast
  • 6.2 liters of 2017 orange blossom honey from Dutch Gold Honey.
  • 9.9 liters of spring water
  • 1 vanilla bean
  • 12 American oak cubes

Specs:

Total Nutrients

  • 16 g Fermaid-O (160 YAN)
  • 11.25g Go-ferm (86 YAN)
  • 8 g Fermaid-K (50 YAN)
  • 10mg of zinc carbonate.
  • 1 tsp potassium bi carbonate
  • Total: 296 YAN

Fermentation:

  • – 3 h – 3.3 g Fermaid-O and 11.25 Go-ferm in a 1.8 liter activated starter.
  • +0 h – mixed up honey and water, pitched starter. 65.8°F
  • +12 h- added 1 tsp of O/K nutrient mix, Signs of off-gassing. 63.5°F. 1.146.
  • + 24 h – degassed and aerated with O2 stone. Added 10mg of zinc carbonate.
  • + 48 h- added ½ tsp potassium bi carbonate, 61.3°Ffermenting. Degassed and added 1tsp nutrient. Gave ½ minute of 02 on full blast since regulator broken. Added ½ tsp of bicarbonate to nutrient mix.
  • +3 days – Gave 1/2 tsp of nutrient mix. Aerated with whip. 62.1°F. Gravity 1.138
  • +4 days – 63°F, gave extra ~1 tsp of Fermaid-O (didn’t measure)- thought I could smell sulfur.
  • +5 day – 62.1F, 1.120, degassed morning, afternoon, eveing.
  • +6 day – degassed am, noon, pm.
  • +7 day – degassed am, noon, pm. 1.108. Added remaining nutrients.
  • +8-11 days – degassed twice a day
  • +12 days – degassed twice a day, 1.072 pm
  • +11-14 days – degassed twice a day
  • +15-17 days – degassed once a day. Still active.
  • +3 weeks – 1.052. Stirred. Still off gassing. Added water to airlock. Added a dozen oak cubes. My kid added an oak cube she had put in her mouth!
  • +5 weeks – Sweet but nice balance with tannin. Transferred to 3 gallon and 1 gallon carboy. Nice. Could use some acidity, maybe tannin. FG 1.040. Added a vanilla bean.

After Fermentation:

  • +5 months. FG 1.040. Transferred all to 15 liter carboy, added two stage clarifier, cold crashed for two weeks
  • +6 months – gave 75 mg of potassium sorbate and 1 g of malic acid and 4 g of acid blend.
  • +7 months – bottled.

Impressions:

The fermentation went really well and the final mead was very clean out of the fermentor. I did not detect any off flavors. For the first year I thought the mead was too sweet. The sweetness was not that of raw honey, just dessert level perception of sweetness which is not my forte. In fact, I was actively trying to get rid of it by blending it with dryer meads. However, after about a year something wonderful happened. The mead became slight oxidized and aged well, and it was a crazy good sipping mead.

I’ve visited Shramms Meads and this mead was not as sweet as some of Shramms that I sampled. The mead is sweet, but not cloying and there was no raw honey. That said, about half the judges knocked at as being too sweet. Either the judges said it was a great sweet traditional or said it was cloying. The range of scores of mead evaluated at the same time really speaks to the variability and quality of judging. Some judges were clearly reaching. Orange blossom is hard to come by in Canada and I expect many of the judges were unfamiliar with dessert-level sweet traditional meads. Honestly, whatever, if you like sweet mead, this one hit it out of the park.

Evaluations:

Session Mead Recipes

This is an evidence-based session mead recipe template that makes remarkable tasting mead in minimal time and turns honey to great tasting mead in a week. The mead recipes are 4-4.5% ABV and are under 100 calories per serving.

The fermentation is straightforward and effort is minimal (~15 minutes to start ferment and <1 hour effort overall). This recipe works well with a wide range of honey profiles, including many wildflowers. All ingredients are easy to find in home brew stores around the world, and no specialty nutrients are required. This recipe template is intended to be a super easy and tasty recipe for veterans and beginners alike.

Recipe: One Week, Crushable, Evidence-Based Short Mead, 4.5% ABV, 4.2 Gallons

Specs:

  • OG: 1.035
  • Expected FG: 1.000
  • ABV ~ 4.5%

Ingredients:

  • 1 packet of US-05 Chico Ale Yeast
  • 2 kg (~4 lbs or 1.4 liters) of honey (golden, late summer, wildflower works well)
  • 15-liter jug of (low mineral) spring water
  • 1 gram calcium chloride (optional)
  • 0.3 grams sea salt (optional)
  • 0.5 grams of gypsum (optional)
  • 0.5 grams of ascorbic acid (optional)
  • 5 grams of Go-ferm (optional)
  • Nutrients, options of (pick one):
    1. 2.1 grams of Fermaid-k/ Energizer and 3 grams of DAP
    2. 1.8 grams of Fermaid-O,1.4 grams of Fermaid-k/ Energizer, and 2 grams of DAP
    3. 3.6 grams of Fermaid-O, 0.7 grams of Fermaid-k/ Energizer, and 1 gram of DAP
  • a 7-gallon wide mouth fermentor (or a second 15-liter jug)

A note on the fermentation vessel

For the recipes involving whole fruit, it is easiest to add everything to a cleaned and sanitized wide mouth 7-gallon jug and mix with a wine whip. You can use a 6 gallon bucket, but you will need to be careful when degassing. Alternatively, split all ingredients between two 15 liter jugs (see pictures) which will avoid all the cleaning. Using liquid honey from glass jars (say two 1 kg jars of honey) is easiest for pouring.

Fermentation (~5 days, 64-72 °F)

  • Time 0 – add all honey, water, Go-ferm and salts (if using Fermaid-O add first addition, 1.77 grams, now). Use a wine whip to agitate aggressively for a couple of minutes, shake both jugs vigorously for at least two minutes, or add one minute of pure O2. Once everything is dissolved, make sure the temperature of the must is between 64-72°F and then sprinkle yeast evenly on top. Add the rubber stopper (usually no. 10) and air lock. This step can be done in less than 15 minutes.
  • +20 minutes, swirl the yeast into solution.
  • +12 hours to 4 days, and at least once a day swirl jugs or mix with wine whip with the lid off. Smell the aroma coming out of the fermentor. Keep temperature steady between 64-72 °F.
  • Staggered Nutrient Timing (degas aggressively before adding nutrients). Choose one of the following:
    1. Inorganic:
      • +12 hours, first dose of nutrients: 1 grams of DAP and 0.7 grams of Fermaid-k.
      • +24 hours, second dose of nutrients: 1 grams of DAP and 0.7 grams of Fermaid-k.
      • +36 hours add final dose of nutrients: 1 grams of DAP and 0.7 grams of Fermaid-k.
    2. Mixed Organic and Inorganic
      • Time 0, add first dose of nutrients: 1.8 grams of Fermaid-O.
      • +18 hours, add second dose of nutrients: 1.8 grams of Fermaid-O. (or 1 grams of DAP and 0.7 grams of Fermaid-k)
      • +36 hours add final dose of nutrients: 1 grams of DAP and 0.7 grams of Fermaid-k.
  • +day 1 – add 30-60 seconds of pure O2 using diffusion stone (optional).
  • +day 3/5 – take gravity readings. It should be 1.000-1.008. Cold crash if desired.
  • +day 4/8 – once gravity is 1.000 add fruit/herbs, if desired, using a large nylon bag. Use the pectic enzyme at this point.
  • ~day 4/8 + 24/48 hours – remove fruit/herbs after 24/48 hours – when vibrant colors are lost in the fruit or leaves.
  • ~day 4/8 + 48 hours once you have reached final gravity – two options:
    1. add 1 gram per gallon of kieselsol and then after 2 to 24 hours add 3.3 grams per gallon of chitosan if a very fast turn around is needed (this addition, and especially at higher levels may reduce aroma, flavor, and acidity and risks adding astringency in fruit meads and traditional meads, but it results in the mead clearing fast). Rack to secondary or into a keg 1-3 days after adding clarifier.
    2. rack back into the 15-liter jug (i.e. secondary). If using two jugs you can rack or pour the two half into one, rinse/repeat then rinse/clean/sanitize and save the extra jug.

Secondary

  • add 0.5 grams of ascorbic acid (and optional 0.5 grams of malic acid) in secondary during or after racking
  • keep stable at a temperature between 64-72 °F if gravity is not yet 1.000. If at 0.9983 it can be keep colder
  • keep in secondary until the mead is reasonably clear, which usually takes 24 hours (i.e. no protein chunks in suspension). You can use the kieselsol and chitosan at this point if you didn’t use it in primary, if it’s having trouble clearing, and you desire it clear.
  • If you shortened or have a floating dip stick, you can secondary in the keg

The recipe yields 16.5 liters plus any volume from the fruit. If you are using fruit, adding another 1.5 liters of water in primary will yield 5 gallons. If going for a traditional mead, you will get 16 liters.

Bottle or Keg for Shelf Stability

Given the level of alcohol of 4.5%, the final gravity will eventually end up at 0.9983, so you should be careful if bottle conditioning for shelf stability. If fermentation stalls at 1.000 then there is 0.0017 residual sweetness left in the mead. If bottling for extended periods of time and your mead is sitting at 1.000 you want to take that residual sweetness into account (reduce honey used for priming sugar by 50 grams).

  • Carbonate to 2.5 vol
  • If bottling for shelf stability:
    • confirm FG is <1.000.
    • rack to a 15-liter jug and add mix in 125 grams of honey diluted 50-50 in warm, non-chlorinated water
    • bottle using a bottling wand, cap
    • place in an area of 62-68 °F for a couple of weeks
  • If kegging you may like to scale the recipe to 5 gallons, then rack into keg and two options:
    1. carbonate to 2.5 vol using CO2 gas
    2. mix in 156 grams of honey diluted 50-50 in warm, non-chlorinated water, place in an area of 62-74 °F for a few days to a couple of weeks

Bottle or Keg for Residual Sweetness

Regarding sweetness, the meads will finish dry at 0.9983. However, S-04 often crashes at 1.000. This leaves residual sugar which, combined with the perceived sweetness from the honey and pomme is offers lots of perceived sweetness. I typically keg at 1.000. Many of the melomels below are balanced at off-dry at the 1.000-1.001 range. You can back sweeten with juice or honey. 

The main issue is that back sweetening with honey can leave mouth coating unfermented honey flavor if you add too much, which may be perceived at approximately 30-50 grams for many of the recipes. To get around this, you can partially ferment added honey in secondary.  

There are three options for residual sweetness. All will be refrigerated as they will no longer be shelf stable. 

  1. Cold crash during primary at desired sweetness, usually 1.000-1.003. Note, you may want to add the fruit/ spice/herbs upfront in this case, but make sure to rehydrate the yeast if doing this.
  2. If using a keg, add fruit juices or honey to taste (in steps of ~15 grams of honey) and immediately carbonate to 2.5 volumes using C02
  3. Finish primary, rack to bottle and keg, add enough sweetness for carbonation and residual sweetness. If bottling, use plastic bottles and refrigerate once the bottles are hard. If kegging, prime with honey, check sweetness level every couple of days and cold crash at the desired level of residual sweetness.

A Short Note on Time Saving

This recipe is designed to work with minimal equipment and with a mind for time saving. One of the biggest time savers is reducing cleaning. Using virgin spring water jugs for primary and secondary means no clean up. Rinse and recycle when done.

If using a 7-gallon fermentor you can leave the wine whip in as the top 1/4 sticks out, so it is easy to reattach back on the drill. The whip is also handy to weigh down bags of herbs and fruit. I also leave my hydrometer in the mead and just take it out every time I stir it with the wine whip. These save dripping mead everywhere and trying to clean and sanitize instruments every time they are used.

Short Mead Recipe Variations

This recipe works really well for dry traditional meads. However, it also works well with additional flavors, and here are some tried and true variations on the recipes. In general, I prefer there to be two complimentary flavors, as there are only a few flavors I prefer to stand on their own.

Add all fruit and herbs, etc., at end of primary to maximize aroma, flavor and body. All whole fruit need to be frozen beforehand and thawed to the temperature of the must (62-77 °F by warming fruit on a stove-top or leave covered at room temperature for ~ 12 hours), and added to a sanitized nylon mesh bag. Similarly, add any herbs/ zest to a nylon bag. If using the two-jug method, avoid whole fruit and use fruit juices or variants with herbs.

  • Traditional
    • use S-04 yeast
    • use inorganic nutrients
    • Keep the temperature stable but slightly higher – between 66-74 °F. If higher, 70-76 °F, make sure to take gravity readings at 24+ hours before step feeding and don’t add nutrients if it’s past the one-third sugar break (gravity of 1.024). If the yeast is not floating on top, you need a higher temperature.
    • increase DAP additions from 1 to 1.3 grams (i.e. low or add a medium amount of YAN)
    • add 1 gram of malic acid in secondary (optional)
  • Lacto Sour Mead
    • direct pitch 50-100 billion count probiotic pills per gallon at yeast pitch
    • select probiotics with predominantly Brevis and Plantarum strains
    • lacto intensifies aroma – use orange blossom or an excellent clover/ wild flower
    • make sure the honey has low floral character, so the mead doesn’t get perfumelike
  • Strawberry and Rhubarb
    • 1.0 kg of strawberry
    • 1.0 kg of rhubarb
    • make sure there is sufficient bicarbonate\ buffering
    • 0.75 grams of pectic enzyme
    • Note for Strawberry with Rhubarb, use 1.5 kg of strawberry and 0.5 kg of rhubarb
    • Remove fruit before 24 hours to avoid extracting Strawberry seed tannin/funk
    • use a very fine mesh bag to avoid residual Strawberry seeds
    • use of kieselsol and chitosan will cut the acid if desired
  • Raspberry
    • 1 kg of raspberries
    • remove fruit after 24 hours
    • use a very fine mesh bag to avoid residual seeds
    • 0.75 grams of pectic enzyme
    • use of kieselsol and chitosan, will cut the acid if desired
  • Cream Soda
    • 2 kg of bright red, sour cherry
    • 1.5 tbsp of vanilla extract
    • add both 0.5 grams of ascorbic acid and 1 gram of malic acid
  • Mojito
    • juice of 4 limes (approx. 1/4 cups, don’t overdo it) using a squeezer
    • leave out the ascorbic acid (optional)
    • zest of 1-2 limes (adds aroma and pithy complexity, use a potato peeler and bag it)
    • 15 x 8-10″ sprigs (tops) of fresh mint (no dirt, spanked, minimal stem, bagged)
    • use US-05 instead of S-04 yeast
  • Thai-Mojito
    • juice of 3 limes (approx. 1/3 cups, don’t overdo it) using a squeezer
    • zest of 1 lime (optional, adds line flavor and aroma, use a potato peeler and bag it)
    • leave out the ascorbic acid (optional)
    • 15 x 8-10″ sprigs (tops) of fresh Thai basil (no dirt, spanked, minimal stem)
    • Use US-05 instead of S-04 yeast
  • Ginger-Lime
    • 1.5 oz of ginger powder
    • 4 oz of fresh minced ginger (add to a bag)
    • juice of 3 limes (approx. 1/3 cups, don’t overdo it)
    • zest of 1 lime (optional, greatly intensifies lime flavor and aroma, use a potato peeler and bag it)
    • leave out the ascorbic acid (optional)
    • optional, for added complexity, add 1/2 gallon of strained ginger bug in secondary or primary
    • for stronger ginger, add powder at pitch
    • Can also substitute lemon for lime if preferred.
  • Jasmine Green Tea
    • ~ 1.5 cups (2/3 of strength of volume) of your favorite loose-leaf jasmine green tea (roasted rice also works great)
    • steep at 175 °F in 1 liter of chlorine free water in a French press for only 3-4 minutes, let cool before adding
    • add juice of 1/4 cup of fresh pressed lemon juice, one zested lemon (optional)
  • Dry Hopped
    • 2-3 oz of juicy/tropical new-world hops
    • dry hop at refrigerator temperature or shorten contact time to 12-24 hours
    • for example, 1.5 oz Citra, 1.5 oz Galaxy
    • use Cryo hops if possible, but make sure to only add half the weight
    • some residual sweetness is nice, FG 1.000-1.003
  • Dry-Hopped Passion Fruit
    • 1 liter (or 0.5 liters of two types) of passion fruit juice (no preservatives) or 2-2.5 kg of fruit blend (dragon fruit has excellent color)
    • dry hop as above
    • some residual sweetness is nice, FG 1.000-1.003

Other tasty variations flavor combination

  • Blackberry and black cardamon
  • Lemonade with ginger bug ferment
  • Black tea, rose water (a cap full), and green cardamon
  • Black tea and lemonade
  • Crab apple juice (1 liter, or cranberry) with all spice, ginger, cinnamon and citrus zests (no cloves!)
  • Cranberry juice (1 liter, or 1 kg red sour cherry or 1 kg strawberry) with 1 can of apple juice concentrate
  • Sour gummy: 1 kg of raspberry, or 1.5 kg red sour cherry or 1.5 kg strawberry, with zest of a lemon, lime and orange, with 1 gram of citric acid (if not using raspberries)
  • Passion fruit, 1 liter of passion fruit juice or 2.5 kg fruit mix (similar to Dry-Hopped Passion Fruit)
  • Pineapple juice (1 liter) and 1 tbsp of smoked chipotle

Recommended flavorings to use with this base:

A Note on Acid Additions

The use of malic acid is not recommended in most recipes because the carbonation is quite high and acidic fruits are often used. However, in others it does bring a mid-palate minerality, a perception of brightness, and can bring a clearer perception of fruit (especially for cherry and strawberry). If you prefer sour gummy candy over non-sour gummy candy, then you will probably prefer the additional malic acid in the traditional, see tasting notes from triangle tests. For the traditional, 1 gram of malic acid adds some brightness, but you can go to 2-2.5 grams if you really want it to pop. You can also use lactic acid, where about 1 gram of 88% lactic acid gives you about the equivalent pH drop of powered acids.

The ascorbic acid (vitamin C) is recommended to be added to most of the recipes. Ascorbic acid is an antioxidant which will help avoid oxidation when transferring and help with color stability. The use is similar to adding K-meta, but does not harm the yeast. It is not added to reduce acidly. Ascorbic acid provides a rounded brightness and helps promote mouthfeel and a perception of fullness. It will also scrub some types of sulfur off-flavors. Generally, 0.5 grams of ascorbic acid is my baseline, but you can go to 1-2 grams if desired.

In the recipes that call for lemons or limes, the juice adds the acidity and some flavor. The zest is used primarily for aroma and flavor. Ascorbic acid does not need to be added when adding lemon or lime juice.

Spring Water and Salt Additions

The recipe calls for the optional salt additions which are used to contribute to mouthfeel, body, and enhance the perception of sweetness. They are used in the same way you use table salt to flavor food. Let’s look at what each of these does.

  • Calcium chloride, (adds Ca, Cl): Helps with flocculation. Contributes body, fullness, complexity and boosts perceived sweetness of honey.
  • Sea salt (adds Na, Cl): Contributes body, fullness, and complexity and boosts perceived sweetness of honey.
  • Gypsum (adds Ca, SO4): Helps with flocculation. Contributes to dryness and a sharp finish. Leave out if you like a persistently sweet finish.
  • Potassium bicarbonate (adds HCO3, K): Contributes body and fullness. Helps buffer the pH drop.

The table below describes the contribution of the salts to the water profile. The first row is a common spring water profile that you can replace with your own. The higher calcium with also add residual alkalinity and help with flocculation.

Here is why each of these are important:

  • Carbonate and Bicarbonate (CO3 and HCO3): Buffers pH drops to avoid phenolics from low pH. Levels in the 200-400 range provide mouthfeel similar to a club soda. Note, if the bicarbonate level of the water is not in the desired range, add potassium bicarbonate (or potassium carbonate). Add 0.5 to 1.4 grams of potassium bicarbonate per gallon if water is low to absent in bicarbonates.
  • Sodium (Na): contributes body and mouthfeel. Levels in the 10-70 mg/l range are normal, levels of up to 150 mg/l are used to enhance malty body and fullness in beers, but levels above 200 mg/l are undesirable.
  • Chloride (Cl): enhances the mouthfeel, complexity and boosts perceived sweetness of honey in low concentrations. Levels in the 10-70 mg/l range are normal. Keep below 150 mg/l and never exceed 200 mg/l. Keep the Chloride to Sulfate ratio to at least 2:1.
  • Sulfate (SO4): Enhances bitterness and adds a dry, sharp, profile to the finish. Avoid if you want a lingering sweetness. High levels of sulfate will create an astringent profile that is not desirable. 5-50 mg/l is recommended
  • Calcium (Ca): Contributes to water hardness and lowers the pH. It is an important yeast nutrient, and levels just over the 100 mg/l are desirable for optimal yeast flocculation. Keep in the range of 50 mg/l to 150 mg/l.
  • Magnesium (Mg): Contributes to water hardness. A critical yeast nutrient and amounts 10-30 mg/l range are desirable. Levels above 30 mg/l may be undesirable unless balanced with calcium levels. Preliminary evidence suggests that this is important to have in your spring water, and not all spring waters contain it. Honestly, I think this is why the fermentation goes so well in my favorite spring water.

Yeast Variations

US-05 dry ale yeast is an excellent option for first time brewers and pros alike. It is very clean, with almost no esters and a cracker/candy profile that lets the honey shine through. It is a more forgiving yeast that is more acid-tolerant, and there is less chance of off flavors. US-05 is also a faster fermentor. US-05 works best for the metheglin-type variants, i.e. Thai-style Mojito, and hopped meads. It also works best for acidic melomels, such as the tropical, rhubarb, and raspberry.

However, IMHO, S-04, with its pear and apple esters, low attenuation, and honey like character is preferred for traditional short meads. That said, it is also more susceptible to just about everything: temperature changes, oxygen levels, inorganic nutrient burn, acidity levels. If you’re an intermediate brewer or better, or have all the elements of the brew down, give it a try for the traditional. This yeast also has a harder time managing organic nutrients and has a sightly higher nutrient requirement.

This recipe is not recommended for wine yeasts which have different nutrient requirements, temperature ranges, and fermentation preferences. For wine yeasts, you need to stagger, and it is much better to use mixed organic-inorganic nutrients or fully organic nutrients. If you use a wine yeast, use EC-1118 (think clean and crisp champagne), and keep temps in the 60-64 °F range. Other wine yeasts often have a wine cooler like flavors/esters, which is very different from this clean ale-like recipe.

Some Kveik strains also work exceptionally well for this recipe. This is especially true if you do not have temperature control and need to ferment somewhere in the 65-105 °F range. Make sure to add plenty of oxygen up front and stagger with a medium level of nutrients (Fermaid-K 2.4g, DAP 4.5g total, or just add an extra feeding at 48 hours). The Stranda and Voss strains are great for metheglins. Avoid any strains, such as Ebbegarden that are said to enhance bitterness as it adds bitterness and ruins the perceived sweetness of honey.

Nutrient Variations: Alternative Staggering and Pitching Upfront

S-04 is one of the few yeasts that can take all the nutrients upfront (all at 2-12 hours). This will bring out extra pear and banana character, but will replace some honey character. Make sure to provide oxygen and use Go-ferm if pitching upfront with S-04. However, staggering is recommended as later generations of yeast are more healthy and may help avoid phenolics cased by mistakes later in fermentation, such as temperature drops and acid fluctuations. This is only recommended if you are in a pinch. For all other yeasts, you should stagger.

The current recommendation for staggering is based on bench trials. S04 will produce phenolics on day 2 if using only inorganic nutrients (DAP/energizer) and you stagger starting right after pitch, also see off-flavor notes below. US-05 yeast is much less prone to off-flavor caused by staggering with inorganic nutrients. If you want to stagger in the first 24 hours, use a low level of nutrients (3.8 grams DAP and 2 grams of Fermaid-k). Make sure all nutrients are in within two days and before the gravity hits 1/3 sugar break, a gravity of 1.024.

Pitch Rate with Yeast Variations

No matter what yeast you use, make sure to pitch both US-05 and S-04 at the recommended 2-3 grams per gallon. The recommended pitch rate of ale yeast is higher than wine yeasts. I have found that a 2-2.5 grams per gallon pitch rate is desirable (see metadata below). A typical home brew yeast packet will say 11.5 grams, but only contains 9.5-9.8 grams.

Use of a “wet” yeast such as WLP001 or Wyeast 1056 may cause sulfur as the pitch rate is several times higher and the yeast are not as well-fed and healthy. You may need to provide a medium level of nutrients for wet yeasts (Fermaid-K 2.4g, DAP 4.5g total, or just add an extra feeding at 48 hours). Again, make sure to stagger. You may also want to pitch half the amount. More experiments are needed here.

Nutrient Levels and Go-ferm

The very low nutrient level recommendation for this recipe is based on triangle tests in the high versus low levels of nutrients with S-04 experiment. It is also based on the metadata at the end of this article, which provides a summary of variations on nutrients and assumptions for this recipe using S-04. Note that the 5 grams of Go-ferm adds 39 ppm YAN which is a huge boost compared to the 44 ppm YAN added using the other nutrients (a low YAN regime is 57-65 ppm YAN total). A low level of nutrients (1.3 grams of DAP instead of 1 gram) will speed fermentation by a couple of days. More experiments are needed to pin down the optimal level of nutrients with and without Go-ferm.

The amount of nutrient account for adding 5 grams of Go-ferm in primary, which you should do if you can. This will help speed up the time between 1.01 and FG, potentially knocking up to a day off fermentation. It also changes the esters slightly towards more apple and less of a pear/banana character with S-04. If you do not have Go-ferm it may be best to adjust your nutrient staggering to 4, 18 and 36 or 4, 24 and 48 hours after pitch. It is also advisable to increase the nutrients by ~30% by either adding 1.3 grams of DAP instead of 1 gram. Also note that Fermaid-O requires the use of Go-ferm, so you may want to avoid organic nutrients if not using Go-ferm.

Use the manufacture instructions with dry ale yeast and pitch directly into the must. You can rehydrate in the Go-ferm, but it is not necessary and do not use the recommended amount of Go-ferm (1.25 grams per gram of yeast) if pitching above 2 grams per gallon. The maximum amount of Go-ferm before it results in off-flavors is approximately 2.5 grams per gallon for S-04 with a pitch rate of 2 grams per gallon and using inorganic nutrients. That said, if you have the time and energy to rehydrate with Go-ferm and know what you are doing, go for it. An experiment is planned to test this.

Nutrient Variations: Inorganic vs organic nutrients

The recipe works very well with the use of only inorganic nutrients. These are readily available anywhere. However, if you have access, you can try mixed organic and inorganic nutrients. Use organic nutrients for the first one or two feedings and then inorganic for later feeding. This may also help avoid phenolics that inorganic nutrients will produce if the nutrients are upfront right after pitch (before 6-12 hours).

Fermaid-O does not have minerals or amino acids, so must be used with Go-ferm. However, it is not advisable to add more than 5 grams of Go-ferm with organic nutrient regimes. Ale yeasts seem to have a much harder time metabolizing organic nutrients, i.e. fermentation my take 3+ weeks, see metadata below. The long fermentation time may also be due to the high calcium (as there is no added magnesium in organic regimes), but more testing is needed here.

This recipe also works with Wyeast nutrient. This nutrient has approximately 0.8 percent of the nutrients of a typical DAP/Fermaid-K regimes (preliminary and forthcoming). Because of S-04’s difficulty with organic nutrients, the fermentation will take up to two weeks. Best to use US-05 if using Wyeast nutrient.

Oxygen

Yeast need oxygen to ferment! It is best to dose with ~60 seconds of pure O2 with a wand and dispersion stone if you can at 24 hours. If using a wide mouth carboy or bucket, sufficient 02 can be added by taking the lid off and aggressively mixing with a wine whip two or three times a day for the first two to four days. However, doing both forced 02 additions and regular wine whip agitation may result in excess oxygen and result in stuck fermentations.

When using jugs for primary fermentation, shaking each of them for 2 minutes aggressively should theoretically add sufficient oxygen, however the metadata evidence suggests that later 02 additions are needed otherwise you can get a slight sulfur character. Especially if you are not adding later 02 with jugs, it may be best to open ferment by covering the opening with a paper towel or coffee filter and elastic band for the first three or four days. You can add water and air lock on day three or four.

In a side by side test, a traditional mead with US-05 was fermented in jugs where one got O2 at 24 hours and the other was just degassed by swirling the jug. Oxygen was added by aerating with a wine whip at the beginning. The traditional without the O2 had strong sulfur character, and the traditional with the O2 was bright and fresh. Don’t be lazy with the O2. Worry about getting enough O2 in during primary, then worry about oxidation at the end of primary. Bench trials are forthcoming on 02 additions.

How to produce off-flavors

Smell the mead every day of fermentation to see how it is feeling. Here are a few possible off-flavors that you’ll be able to smell if you don’t follow this recipe exactly.

  1. Phenolic (more common) – smells like mothball, rubber, or band-aid
  2. Sulfur – at low levels like a warm American lager beer or muddled esters, at high levels smells like rotten egg
  3. Diacetyl – smells and tastes like butterscotch, sometimes caramel or artificial butter

You can get off-flavors if you do the following:

  1. Forgot the nutrients, added too much yeast, or forgot to aerate (sulfur, maybe recoverable)
    • If you smell sulfur, you probably forgot the nutrients, added too much yeast, or didn’t add enough O2. If you did add the O2 and nutrients, the yeast will clean this up, and it is not likely to be noticeable in your final mead.
  2. Stagger with a DAP addition within the first 6-12 hours (phenolics, recoverable)
    • Light phenolics will noticeable during fermentation if you stagger using DAP nutrients and your first nutrient addition is within 6-12 hours (including DAP/ Fermaid-K/ Wyeast) with S-04 (especially at medium-nutrient levels). This may blow off in the final product. This is less of a concern for US-05.
  3. Letting the temperature drop below 60 °F or above 72 °F (phenolics if using inorganic, sulfur if organic, likely recoverable)
  4. Adding acidic fruits during peak fermentation (phenolics, likely unrecoverable)
    • Make sure only to add fruit once fermentation has slowed considerably <1.004. Make sure your fruit additions do not drop the pH below 3.0. If they will, make sure only to add fruit once FG is 1.000. Both the tropical fruit and rhubarb mead will get you close to a pH of 3.0 so don’t boost the level of fruit beyond the recipe, add extra potassium bicarbonate, or make sure the fermentation is complete before adding. S-04 is more susceptible to pH drops below 2.9 than US-05 but it can still happen for both.
  5. Adding more nutrients towards the end (phenolics, unrecoverable)
    • A for sure way to ruin the mead completely is by deciding it is not finishing up quickly enough and adding more nutrients that include DAP after a gravity of 1.012. For example, if the mead is sitting at 1.004, and you are getting impatient, do not add more nutrients (DAP/Fermaid-k or Wyeast). This will ruin your mead and is not likely to clean up. Adding Fermaid-O at this stage will help speed fermentation slightly, but may not be metabolized this late in fermentation, so may be noticeable in the final mead. Best to keep the temperature steady, and wait it out.
  6. Use chlorinated tap water (phenolics, unrecoverable)

If you get diacetyl leave the mead in primary and raise the temperature a few degrees for a couple more days.

In summary keep to the recipe.

What makes this an evidence-based recipe?

This recipe has been derived using evidence from many triangle tests and bench trials. Some experiments have been completed, some are ready for triangle tests, but more can always be completed. The recipe will be updated as new evidence arises. Here are the experiments that support the best practices for the recipe:

Preliminary evidence from metadata and experiments to be repeated (see metadata below)

  • 1 gram versus 2 grams per gallon pitch rate with S-04 (done in three side-by-sides)
    • evidence that the pitch rate matters but that 2 grams was preferred
  • S-04 vs Kviek and other English Strains
    • evidence that S-04 and Kviek performed best, but that only S-04 can handle nutrients upfront.
  • Oxygenation method – shaking vs wine whip vs forced O2 in closed primary fermentations
    • evidence that shaking carboy for 1-2 min may be insufficient for aeration in closed fermentations.
  • Tosna 3.0 vs inorganic nutrients using S-04
    • evidence that the pitch rate Go-ferm off-flavor taste threshold for Tonsa 3.0 is lower.
    • evidence that organic nutrients are sluggish with ale yeast and can result in souring

The fermentation characteristics and other evidence can be seen in the following metadata across these studies.

Metadata

The tables below list the metadata for fermentation with S-04 and US-05. All fermentations listed in the table have SG between 1.030 – 1.038.

Metadata for S-04

Metadata for US-05

Metadata Legend

“Degas”, refers to degassing method:

  • “whip” refers to using a wine whip to degas,
  • “shake” is aggressive degas, and
  • “swirl” is swirling of jugs which is less aggressive.

“Pure O2”, refers to oxygenation method:

  • “day #” is the use of pure oxygen with a diffusion stone,
  • “shake” is a 2-minute shaking of a jug with 50 percent headspace, and
  • “whip” refers to aggressive agitation with a wine whip to during mixing and 2-3 times a day for the first three days.

“Nutrient Level”, refers to level of YAN in ppm (does not include Go-ferm):

  • 0.83 is a low level of nutrients, 65.2 ppm YAN (3.9 DAP, 2.1 Fermaid-K)
  • 1 is a medium level of nutrients, 78.3 ppm YAN (4.7 DAP, 2.5 Fermaid-K)
  • 1.38 is a high level of nutrients, 108.7 ppm YAN (6.6 DAP, 3.5 Fermaid-K)