Anecdotal

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, 62-68 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 62-68°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 62-68 °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 between 62-68 °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 62-68 °F for 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 (62-68 °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
    • 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 recipes 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 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)

Tailored Additions of Nutrients With Go-ferm (TANG 2.0)

Want to avoid brine/ umami off-flavors, especially in short meads? This article proposes taking the YAN contribution from Go-ferm into account and avoid excessive nutrients based on pitch rates and low ABV levels.

A common complaint for short meads is that they can have a briny/ umami flavor. I have lost 1 gallon short mead batches to these off-flavors when using nutrient calculators such as the Meadmakr nutrient calculators. This is also a common compliant for many who have tried to replicate public recipes of the short meads published by Groennfell or Havoc Meadery and didn’t have Wyeast Yeast Nutrient.  But what makes these off-flavors more likely in short meads and in small batches?

From my experience, the umami flavor (think wet dog food/ aged cheese) is because the YAN contribution of Go-ferm rehydration nutrient is ignored in nutrient calculators.  The Scott Labs 2016 Handbook suggests that when using a dose of 25 g/hL Go-ferm adds 7.5 mgN/L. This is three-quarters of the YAN contribution compared to Fermaid-O. However, no current calculator takes this into account! Also, the combination of Fermaid-K and Go-ferm can add quite a bit of minerals to your water profile, which can result in mineral off flavors.

The extent of the biases induced by Go-ferm in nutrient calculators is a larger problem in short meads and smaller batch sizes, but still exists in larger volumes and higher gravity. This article discusses biases in nutrient calculators and other factors that calculators to not consider, such as acid, oxygen and pitch rates/ wet yeast. It also provides a recommendation for a revised best practice for nutrient regimes when using Go-ferm. I call it Tailored Additions of Nutrients with Go-ferm (TANG). Basically, the biggest takeaway is that while it is often said it is hard to over-pitch, it is possible to over pitch if using Go-ferm with the recommended rehydration protocols.

YAN Overload Example: a 5 gallon 7% ABV sparkling dry traditional mead using the default Fermaid-O / Fermaid-K / DAP nutrient protocol for a yeast with a low nutrient need from the The MeadMakr BatchBuildr.  Recommended YAN is 99 as suggested in the Scott Labs Handbook. The MeadMakr Advanced Nutrient Calculator recommends 10 grams of dry yeast, and the following nutrients:

  • Go-ferm: 12.5g (79.4 YAN)
  • Fermaid-O: 8.5g (72 YAN)
  • Fermaid-K: 5.1g (27 YAN)

In this example, you can see the total YAN addition inclusive of Go-ferm is 178.4 YAN, 80 percent more than the recommended 99 YAN. Why would this matter? Well, if you took the nutrient calculator and try to have Fermaid-O provide the extra 99 YAN, any addition of Fermaid-O above 8.5g would give you a warning that it “risks adding yeasty flavors.” Go-ferm is mostly deactivated yeast cells so such a large addition of Go-ferm with this protocol would most likely add yeasty flavors.

This example could be further compounded if one tried to follow Groennfell’s recipes and pitched with 5 grams of yeast per gallon. In such a case you would rehydrate 25 grams of yeast using 31.5 grams of Go-ferm (using 1.25 g of Go-ferm per gram of dry yeast), which would contribute 198.5 YAN from the Go-ferm alone, 200 percent the recommended YAN. It is also a bigger problem in smaller batches, due to rounding up to a full packet of yeast, see examples below.

The Pitch Rate and ABV Biases:

The below figure depicts the recommended and actual YAN contributions, which include the YAN contribution from Go-ferm. The recommended YAN and Go-ferm amounts are from the The MeadMakr BatchBuildr. The meads are a 6.5% ABV dry traditional mead, and a 14% ABV traditional mead finishing at 1.01, both with a low YAN requirement yeast. The nutrient regime is the Fermaid-O / Fermaid-K / DAP which is based on Travis Blount-Elliott’s white paper, but the values do not depend on the nutrient regimes using the protocols from The MeadMakr BatchBuilder.

yanGraph.png

You can see here that the problem of high YAN is larger in smaller batches, especially for one gallon batches. At one gallon batch sizes, for the lower ABV mead, the total YAN taking into account the contribution of Go-ferm is over three times the recommended amount, and has 100 more YAN than a two gallon batch.  At one gallon batch size, total YAN is twice as high for the higher ABV mead and again has 100 more YAN than a two gallon batch. This reflects two things:

  1. Pitch Rate Bias: introduced by not pitching a constant amount of yeast/Go-ferm per gallon (and using Go-ferm at 1.25 weight)
  2. ABV Bias: introduced by using the same amount of yeast/Go-ferm per ABV level

The Pitch Rate Bias is driven by not pitching a consistent amount of yeast per gallon and is what drives the downward and fluctuating total YAN by volume. The ABV Bias is driven by adding a consistent amount of Go-ferm for each ABV level and is what drives a constant gap between the recommended and total YAN even at high volumes of must. The total YAN is 90% higher than recommended at 12 gallons for the 6.5% ABV must, but only 40% higher than recommended at 12 gallons for the 14% ABV must. Hence, the Pitch Rate Bias is more of a problem for small batch sizes, but the ABV Bias is more of a problem for smaller ABV meads compared to higher ABV meads. 

The Pitch Rate Bias does not exist for the TOSNA 2.0 regime in the MeadMakr TOSNA 2.0 Calculator, but does still exist if you use the TOSNA 2.0 regime in The MeadMakr BatchBuildr if rounding up to full packets of yeast. Lets look at the TOSNA 2.0 regime and using 2 grams of yeast per gallon to see what we get.

yanGraph_tosna.png

Note that in the figure, the recommended YAN number comes from the MeadMakr BatchBuildr (since this article has been published the calculator changed the wording of “YAN recommended” has been changed to “YAN provided”). You can clearly see that the pitch rate bias is lost – the amounts of YAN are constant for each volume of must. However, since the pitch rate is the same for both the 6.5% and 14% ABV meads, the contribution of Go-ferm adds a constant amount of YAN to the total YAN for both meads. This can be seen by comparing the total and recommended YAN in  TOSNA 2.0 by ABV level.

t2_rec.png

The contribution of the YAN from the Go-ferm is a constant amount of YAN added to the YAN contributed from Fermaid-O. How different the total and recommended is by ABV can be seen from the below figure.

t2_excess.png

For a 4% ABV short mead, the total YAN is 90% higher than recommended whereas for an 11.5% ABV standard mead, the total YAN is only 30% higher than recommended.

The Pitch Rate and ABV Biases: TOSNA 3.0 (Updated April 2019)

Since this article was first published in October 2017, TOSNA 3.0 was released. TOSNA 3.0 comes with a nice new calculator, but the main difference in terms of nutrients is that the pitch rate differs by OG. Let’s see what changed.

The below graph shows the YAN for two meads using TOSNA 3.0.The meads evaluated are a 6.5% ABV dry traditional mead, and a 14% ABV traditional mead finishing at 1.01, both with a low YAN requirement yeast. For the low ABV mead, the lower pitch rate means that less YAN is added from the Go-ferm and the excess total YAN from recommended drops from 71 percent to only 28 percent. The total YAN for the high ABV mead is the same, nothing changed since 2 grams per gallon are pitched for the starting gravity.

YANtosna3.0bygallon.png

Now we compare the total and recommended YAN in TOSNA 3.0 by ABV level. Notice that relative to TOSNA 2.0 regime in The MeadMakr BatchBuildr and using 2 grams of yeast per gallon, TOSNA 3.0 has YAN provided that is closer to the recommended levels. There are three big jumps in the curve when the pitch rate adjusts.

YANtosna3.0byABV.png

Since the YAN contribution from the Go-ferm is no longer constant in TOSNA 3.0, the excess YAN contributed from Fermaid-O. How different the total provided and recommended by ABV can be seen from the below figure. For a 6.3% ABV dry short mead, the total YAN is 27% higher than recommended (compared to 70% in TOSNA 2.0) whereas for a 14.1% ABV dry mead, the total YAN is only 4.8% higher than recommended (compared to 25% in TOSNA 2.0).

YANtosna3.0excess.png

Basically, compared to TOSNA 2.0TOSNA 3.0 reduces its ABV bias but also introduces a pitch rate bias. The pitch rate bias is due to the gravity levels at which the pitch rate adjusts, 1.110, 1.130, and 1.160.

Severity of the Biases

Lets stop and reflect for a second on the severity of the biases.

  1. The pitch rate bias is the largest for one gallon batches if rounding to full packets, and is clearly inconsistent with recommendations. Not rounding to full 5 gram packets or varying the amount of yeast steadily by starting Brix can easily fix this.
  2. The ABV bias from not taking into account the contribution of Go-ferm by ABV is really an argument about how much YAN to add (the appropriate Recommended/Provided YAN level), and is more debatable. Slightly higher nutrients than the recommended level are probably beneficial and prudent in meads (also smaller pitch rates, more oxygen additions, higher temperatures, or anything else that increases nutrient uptake), but for short meads with high pitch rates, the additional nutrients from Go-ferm may be detectable. Moreover, nutrients are expensive, and an overload can encourage spoilage. Also, you want your yeast to clean up fermentation by-products (such as acetaldehyde) and too many nutrients may make your yeast lazy, and less prone to cleaning up.

So, how much extra YAN should be provided? If meads are harder to ferment than wine, maybe 10-30 percent before excess mineral off flavors are noticed. Maybe this is also because mead makers use different fermentation practice: adding the extra oxygen, degassing, etc. I have pitched meads at exactly the Scott labs handbook guidelines with a YAN of 10*Brix*Gravity*NutrientMultiplier. Most turned out fine, some higher gravity meads slowed down around 12-13 percent ABV (for a 14 percent semi sweet trad using 71B). Let’s look at some possible alternatives.

Potential Alternatives

The 2017 Scott Labs Handbook recommendations a pitch rate of 0.95 grams/gallon up to 25 brix, 1.33 grams/gallon from 25-30 brix and 1.5 grams/gallon from 30+brix. They also say 1.9 grams/gallon for ice wine. We can look at what this provides in terms of excess YAN compared to their recommended level.

We can also compare to a method that pitches yeast to pin down the desired excess nutrients. In this case, the pitch rate in terms of grams per gallon can be given by the following formula.

grams/gallon=(Brix*(1+(percent excess)/100)-(YAN from Fermaid-O))/39.63

Where percent excess could be say, 20 or 40 percent. Let’s use the TOSNA 2.0/3.0 recommended amount of Fermaid-O and its YAN contribution and see what happens to pitch rates using this formula. Let’s also compare it to the Scott labs handbook pitch rate and the TOSNA 3.0 pitch rate.

pitch rates.png

As can be seen the TOSNA 3.0 and the Scott labs handbook pitch rate are the same below 25 Brix, so too is the excess nutrients. The main difference is that the Scott labs handbook pitch rate is below 10 percent excess nutrients for meads below 10 percent ABV. In contrast, maintaining constant excess nutrients gives similar pitch rates, but falls to close to half a gram per gallon at around 8.2 Brix.

excess.png

Scott labs has stated that the contribution of Go-ferm is not likely to result in off-flavors. This is consistent with the fact that they are recommending the use of Go-ferm in wines which are likely to have staring Brix above 19 (10 % ABV potential). This only results in at most 10 percent excess nutrients, which, yes, should be fine. However, meads makers who ferment below 14 Brix quickly enter the range where excess YAN from Go-ferm can become excessive. Moreover, from experiments, the 18 to 20 Brix range can quickly result in sluggish and stick fermentation because this is when the YAN levels are the lowest. This is especially true when wet yeast packets are pitched due to their higher pitch rates and nutrient needs.

Experimeads Evidence for Go-ferm Off-flavors

Pitch Rate: 1 gram versus 5 grams per gallon. This article found that all else equal, a five gram per gallon pitch rate combined with the recommended amount of Go-ferm resulted in significant off-flavors compared to a mead with only 1 gram pitch rate with the recommended amount of Go-ferm.

Go-ferm Pitch Rate Off-Flavor Threshold: Inorganic. This article found that in a session mead fermented with ale yeast, Go-ferm off-flavors were detectable above the 2.5 grams per gallon pitch rate. The preferred mead by both judges was the mead pitched with 1.25 grams of Go-ferm per gallon, with the higher pitch rate.

Water Mineral Profile

While water mineral profiles is an important topic in making beer, it is mostly overlooked in mead making. This must change. It is important to consider your water mineral profile from the combined minerals from the salts in the water and additions from nutrients. This is complicated by the fact that mineral contribution is not published with various nutrients.

Go-ferm and Fermaid-K have minerals in the nutrient, whereas DAP and Fermaid-O do not (although, they naturally exist in the yeast hulls in Fermaid-O). Thus, in excessive amounts Go-ferm and Fermaid-K risk adding mineral or brine character depending on the mineral profile of the water. I have used all nutrient protocols with either spring water, 50/50 spring water and distilled water, and filtered city water to make meads. I found that the spring water gave me a brine flavor (especially in short meads) and the filtered tap water did not. The table below shows the mineral profile for an example of a typical natural spring water from Kingston, Ontario, Canada:

spring

In contrast, the Bicarbonate and Calcium levels of the Kingston, Ontario tap water are more than half of that of the spring water:

kingston

I also noticed that the spring water gave much better flocculation of the yeast compared to the filtered city water, something that I attribute to the higher calcium levels. The same nutrient additions to the above two water profiles will give very different mineral contents in the final product.

Just for fun, lets compare this to the Ozarka® Brand Natural Spring Water that Bray Denard prefers to use in his BOMM recipes.

ozark

Here I report the highest values in the 2016 water analysis. You can see that the water profile recommended for the BOMM is very light on minerals. In fact, the total dissolved minerals in the Ozarka® Brand Natural Spring Water is 20-120 ppm. This puts the water in the slight to moderate mineral content range. In contrast, the water profile of the Kingston Ontario City water is 120-140 putting it in the moderate to high mineral content range and the natural spring water that is sold in Ontario is 300 ppm, which has high mineral content.

The low mineral levels of the Ozarka® Brand Natural Spring Water may be why Bray adds potassium bi-carbinate to his meads – as there is less minerals to buffer against the PH drop compared to a higher bi-carbonate water. An interesting question: do you need to add potassium bi-carbinate (or potassium carbonate ) depending on the original carbonate levels of your water? Probably not if you have high mineral content water.

It is also notable that Sergio Moutela owner of Melovino Meadery and creator of TOSNA 2.0, uses reverse osmosis water in his mead making. While there has been little attention attached to water profiles/ building water profiles from nutrients, this is likely to be a topic explored in the future.

From my experience (and using Brays and Sergios success), when using Go-ferm or Fermaid-K you want water with lower mineral levels to avoid mineral off-flavors.

Experimeads Evidence for Mead Water Chemistry

High Chloride to Sulfate Ratio: tasters were unable to significantly distinguish between a mead with a balanced versus higher chloride to sulfate ratio with a mead dosed post fermentation. However, most participants who correctly identified the odd mead out preferred the mead with higher chloride to sulfate ratio.

High Mineral versus Low Mineral Content. tasters were unable to significantly distinguish between a mead with a lower chloride to sulfate levels with a mead with higher levels. However, most participants who correctly identified the odd mead out preferred the mead with higher mineral content.

Staggered nutrients

I generally recommend following a staggered nutrient regime. Use what TOSNA 3.0 recommends if using TOSNA 3.0 for high ABV meads. Note that Sergio has recommended pitching all organic nutrients up front for session meads, but this is not reflected on the calculator. If deviating, I would suggest keeping in mind the following:

  1. For session strength meads, I recommend the timing in the Short Mead Recipes, which is based on bench trials on staggering in session meads.
  2. For standard/ sack meads follow the standard day 1, 2, 3, and 1/3 sugar break. Make sure the nutrients are in well below 8% ABV.

Oxygen, Temperature, PH:

The optimal YAN needed varies by oxygen, temperature, PH levels. I suspect that in the future, these will be added to nutrient calculators. Where’s why:

Oxygen: The more additions of oxygen will delay/restart the lag phase and increase the yeast count, and result in more nutrient absorption. Make sure to stagger nutrients to ensure that there is plenty of YAN/ micronutrients for the lag phases induced by the oxygen additions. From Scott Labs 2017 Handbook page 36: “When adding more oxygen to the must/juice, nitrogen is captured faster and more is needed when compared to fermentations taking place under anaerobic conditions.” You can easily get a stuck mead if you are adding recommended levels of YAN but are adding lots of oxygen, even in short meads.

Temperature: The warmer the temperature, the faster the lag phase and fermentation, so you want to get your nutrients in sooner to ensure that there is plenty of YAN/ micronutrients. From Scott Labs 2017 Handbook page 36: “An increase in temperature stimulates the growth of yeast and fermentation rate, thereby requiring increased levels of nitrogen.”

PH: The lower the PH, the more stress of the yeast and the harder it can be for the yeast to absorb nutrients. From Scott Labs 2017 Handbook page 36: “At pH 3 only 70% of ammonia can be utilized compared with > 90% at pH 4. This can modify the handling of acidic whites or high pH reds.”

Oxygen, Temperature, PH YAN Multipliers: Ideally, Scott Labs would provide multipliers just like they have for the yeast requirement multiplier. Let’s look at the yeast multipliers.

  • For Low N requiring strains: 0.75
  • For Medium N requiring strains: 0.90
  • For High N requiring strains: 1.25

Going from a Low N to a Medium N requirement and a Medium N to High N requirement represents a 20 and 33 percent increase in the total recommended YAN. This range may be useful a benchmark excess multipliers for how to increase the nutrients/pitch rates in a high oxygen, high temperature, or low PH environments. If these multipliers were provided by Scott Labs I expect they would be added to nutrient calculators.

Another way of putting this is that recommendations of nutrient regimes should always be accompanied by recommendations of oxygen amounts and timing.

Ale and Wet Yeasts 

Ale yeasts manufacturers recommend pitching at 2-3 grams per gallon. The recommended pitch rate of ale yeast is higher than wine yeasts. In this case, for low ABV meads, it is best to add .25 grams of Go-ferm per gallon and not add the 1.25 grams of Go-ferm per gram of yeast. Based on bench trials, the amount of Go-ferm before off-flavors are detectable in session meads is above the 2.5 gram pitch rate with the recommended amount of Go-ferm per gram of yeast pitched.

Wet yeast such as White labs, Wyeast, Escarpment Labs, need more nutrients as the pitch rate is several times higher. Moreover, the yeast is not as well-fed and healthy. You may need to provide a higher level of nutrients for wet yeasts. I often do this by adding a fourth feeding in session meads. Despite not needing to be rehydrated, it is still prudent to add Go-ferm at 1.25 grams per gallon. This can be added at pitch or in an activated starter. The use of Go-ferm in this case is especially necessary when using Tosna 3.0 as Fermaid-O does not contain the needed minerals or amino acids.

Tailored Additions of Nutrients with Go-ferm (TANG 2.0) :

Tailored Additions of Nutrients with Go-ferm (TANG) is not a nutrient protocol, just a philosophy. Use TOSNA 3.0 and/or similar protocols, especially for Brixs above 17. Just remember that when using Go-ferm and online calculators:

  • Avoid the pitch rate bias by tailoring your yeast pitch to the original gravity. Don’t round up. Use TOSNA 3.0 or Scott Labs Handbook recommendations on pitch rate.
  • If you deviate from these recommended pitch rates, take at least some of the YAN contribution of Go-ferm into account (especially in short meads). Using 1.25 grams per gallon regardless of pitch rate is prudent.
  • Increase the YAN requirement of the yeast in a high temp, high oxygen, or low PH environment by approximately 15-30 percent using organic sources.
  • Taylor your water mineral profile and watch the combined mineral content of the water and nutrients.

To calculate the YAN contribution from Go-ferm, pretend it is Fermaid-O with an effectiveness of 3 using The MeadMakr Advanced Nutrient Calculator. If the equivalent amount of Go-ferm in Fermaid-O gives a warning of adding yeasty flavors in the calculator, reduce the amount of Go-ferm. If you want to do the calculations for other types of nutrients, see the YAN contribution of common nutrients.

The reason I suggest the use of Go-ferm and/or Fermaid-K with Fermaid-O is because it is recommended by Scott Labs, the creator of these products. As stated in Scott Labs 2016 hand book:

“Fermaid O does not contain any DAP or supplemented micronutrients. For optimal results, Fermaid O should be used in conjunction with an appropriate yeast rehydration nutrient (GoFerm or Go-ferm Protect Evolution) to assure proper micronutrient nutrition of selected yeast from rehydration through completed fermentation.”

Hence, you should use Go-ferm and/or Fermaid-K in conjunction with Fermaid-O to get some micronutrients.

Another option, as mentioned by Jeff at The Mead House Podcast when TANG was discussed on Episode 67, is to not use Go-ferm at all for low gravity meads. Osmotic stress to yeast only really kicks in at 1.104 OG or higher, so Go-ferm may not be totally necessary at lower gravity. This may work as the rehydrated yeast should already have a store of minerals and amino acids, needed for the quick fermentation of a short mead. However, I still recommend the use of Go-ferm even at low gravity. First, because Scott Labs recommends it. Second, because in session meads, bench trails show that some go-ferm benefits fer mention and flavor.

What should the pitch rate be for a mead?  Groennfell meadery  pitches at 5 g per gallon but doesn’t use Go-ferm. Ken Schramm of Schramm’s Mead pitches at 3-4 g per gallon but his meads are huge. Michael Fairbrother of Moonlight meadery pitches at 1 g per gallon. TOSNA 3.0 varies the pitch rate from 1 to 4 grams per gallon depending on starting gravity. Experimead bench trials and experience tells me that pitch rates above 3 grams and above result in increased risk of nutrient off-flavors and spoilage. Nutrient calculators should warn of off-flavors if the pitch rate is too high at certain ABV levels, and you use the recommended amount of Go-ferm.

But beware: there is very little evidence of how pitch rate interacts with recommended YAN to affect the presence of off-flavors. Higher pitch rates do need more nutrients, but not as much as Go-ferm provides at lower ABV levels.

TANG example 1: Nutrients for a 5 gallon batch of my 8 % ABV lemon basil mead with scored 40/50 and 45/50 in the Winnipeg 2017 Pro/ Am Brew Challenge. Recommended YAN is 112.5 as suggested in the Scott Labs Handbook. The MeadMakr BatchBuildr  gives the following:

  • 10 g yeast
  • Go-ferm: 12.5g (80 YAN)
  • Fermaid-O: 8.5g (72 YAN)
  • Fermaid-K: 7.7g (40.5 YAN)
  • Total actual YAN: 192.5

TANG (here I use DAP because of the use of high mineral content spring water)

  • 10 g yeast
  • Go-ferm: 8.5 g (Contributed 58 YAN)
  • Fermaid-K: 3 g (Contributed 16 YAN)
  • DAP: 3.8 g (Contributed 41 YAN)
  • Total actual YAN: 112.5

In this case you can see how the rehydration in Go-ferm would have resulted in excessive YAN additions using the The MeadMakr BatchBuildr. Taking this into account and tailoring nutrients to the water profile by using DAP to not add more minerals earned me silver and a 45/50 score for a bottle conditioned bone-dry short mead.

TANG example 2: nutrients for a one gallon batch of my 6.5 % ABV dry traditional short oaked mead. Recommended YAN is 92.2 and The MeadMakr BatchBuildr gives the following:

  • Go-ferm: 6.25g (200 YAN)
  • Fermaid-O: 1.7g (72 YAN)
  • Fermaid-K: 0.76g (20.2 YAN)
  • Total actual YAN: 292.2

TANG (here I have water with low minearl content so use Go-ferm and  Fermaid-K)

  • Go-ferm: 1.65 g (52.2 YAN)
  • Fermaid-K: 1.5 grams (40 YAN)
  • Total actual YAN: 92.2 YAN

In this case you can see how the problem of YAN provided by Go-ferm is exaggerated in lower batch sizes. Taking this into account and tailoring my nutrients reduces the risk of off-flavors.

TANG example 3: nutrients for a 5 gallon batch of 6.9 % ABV mead from Groennfell Meadery. I have made several of the recipes following the guidelines put forth in “How we brew everything we brew.” This includes fermenting at high temps, pitching 25 grams of D-47, and putting all nutrients in at pitch. All the meads turned out great using TANG. I always use water with a low mineral profile from a low mineral profile spring water or a higher mineral spring water diluted with distilled water with only Go-ferm and Fermaid-K. Recommended YAN by Scott Labs Handbook is 99 YAN. The MeadMakr BatchBuildr with your own hih pitch rate would give you the following:

  • Go-ferm: 31.25g (198 YAN) – assuming you use Scott Labs Guidelines of 1.25g/g yeast
  • Fermaid-O: 8.5g (72 YAN)
  • Fermaid-K: 5.1g (27 YAN)
  • Total actual YAN: 297

TANG  (here I have low mineral content water so use Fermaid-K)

  • Go-ferm: 8.5 g (54 YAN)
  • Fermaid-K: 8.5 grams (45 YAN)
  • Fermaid-O: 8.5g (72 YAN)
  • Total actual YAN: 171 YAN

In this case you can see how high pitch rates and the use of Go-ferm can triple the actual YAN additions. Taking this into account and tailoring nutrients reduces the risk of off-flavors.

TANG example 4 (TOSNA 3.0): nutrients for a 3 gallon batch of 12 % ABV (1.09 SG) traditional dry mead using a yeast with a low nutrient requirement. 162 YAN is recommended by the Scott Labs Handbook. Note, if you select the Fermaid-O (TOSNA 2.0) regime in the MeadMakr BatchBuildr you get a different recommendation than the TOSNA 3.0.  Lets review both.

The MeadMakr BatchBuildr for low nutrient yeast, Fermaid-O/ TOSNA 2.0, with 10 grams of yeast and the following nutrients:

  • Go-ferm: 12.5g (132 YAN)
  • Fermaid-O: 9.7g (137 YAN)
  • Total actual YAN: 269

MeadMakr TOSNA 3.0 Calculator is 3 grams of yeast and the following nutrients:

  • Go-ferm: 3.8g (40 YAN)
  • Fermaid-O: 9.7g (137 YAN)
  • Total actual YAN: 177

In this case you can see that the overall YAN is highest for The MeadMakr BatchBuildr but still high for TOSNA 3.0. I recommend staying with TOSNA 3.0 exactly at the recommended pitch rates for higher ABV meads.

Conclusion

It seems that some calculators use the 1.25 grams of Go-ferm per gram of yeast pitched as a hard and fast rule. You either use Go-ferm or you don’t. However, why would some calculators ignore the YAN and mineral contribution from Go-ferm? If you want to avoid brine/mineral off flavors and help the yeast clean up any extra off-flavors (like acetaldehyde) you may want to keep the following tips TANG in mind:

  • Avoid the pitch rate bias by tailoring your yeast pitch to the original gravity.
  • Take the YAN contribution of Go-ferm into account (especially in short meads).
  • Increase the YAN requirement of the yeast in a high temp, high oxygen, or low PH environment.
  • Use low mineral content water or watch the combined mineral content of the water and nutrients.

There is undoubtedly a range of YAN that is a safe zone around the recommended YAN, conditional on your process, that ensures yeast health and reduces the risk of off-flavors. Keep in mind that even though you may not be noticing mineral and yeast off flavors, other off-flavors may not be as readily cleaned up.

This article shows some biases in calculators, but undoubtedly more research is needed. More research is needed to answer the following questions.

  • What are the nutrient taste thresholds for the different regimes by ABV levels?
  • What are the taste thresholds of water mineral profiles for different ABV levels?
  • YAN multipliers for the pitch rate, oxygen, and temperature ranges?

This deserves full-blown experiments. Experimeads are currently in progress, so stay tuned. The TANG protocol is currently a philosophy rather than a complete protocol. Use TOSNA 3.0, but if you deviate from the protocol, keep TANG in mind.

Assumptions

The following are used in the above calculations:

  • Scott labs handbook recommended YAN: 10*Brix*Gravity*NutrientMultiplier.
  • DAP 1g/L = 210 YAN
  • FERM K 1g/L = 100 YAN
  • FERM O 1g/L = 40 YAN (Effectiveness multiplier of 4 so 160 mgN/g/L equivalent.)
  • Go-Ferm 1g/L = 30 YAN (Effectiveness multiplier of 4 so 120 mgN/g/L equivalent.)