Summary: Tonight we talked about Sergio Moutela’s TOSNA and how to calculate the nitrogen needs for your nutrient additions. Below are Aaron’s notes from tonight. Also want to thank Brett Tennant from Calgary, Alberta Canada for joining us to talk about his chocolate mead, and What’s In The Hopper. Walk through of TOSNA calculation. Start with your starting brix (in this case, 21 brix). That determines your target milligrams of Nitrogen per Liter. 21 brix = 200 mg N/L Take your target mg N/L and divide by 50. 200 divided by 50 = 4. Then you multiply that by the number of gallons, 3 times 4 = 12. That is the number of total grams of Fermaid O to use. Divide that by 4, and that would be how much Fermaid O to use during each nutrient addition. 12 divided by 4 = 3 grams per nutrient addition. If you don’t want to do the calculation and just want to look it up in a table, here is a table filled out for different starting brix levels as well as different batch sizes (1, 3 and 5). TOSNA also requires that you calculate the amount of yeast. Here are the steps: For 21 brix, you would use 1 gram of yeast per gallon. In this case, it would be 3 gallons, so 3 grams of yeast. Multiply the grams of yeast by 1.25, and that’s how much go-ferm to use. 3 times 1.25 = 3.75 grams of go-ferm. Multiply the grams of go-ferm by 20. That’s how many ml of water to use. 75 times 20 = 75 ml (or grams) of water. 1 ml = 1 gram of water. Same as above, here is a table if you don’t want to do the calculations.
