Fermaid-O for a must, split into TOSNA's four additions.
Honey has around 30 ppm of nitrogen, against the 150–200 ppm a healthy
fermentation needs, which is why a mead fermented without nutrient can take
a year to lose its sulphur. TOSNA (Sergio Moutela's Tailored Organic
Staggered Nutrient Addition) sizes the dose from the must's sugar and the
strain's demand, and staggers it so the nitrogen arrives while the yeast
can still take it up.
(((Brix × 10) × N requirement factor) /50) × batch size in gallons = total grams of Fermaid-O
with the factors 0.75 / 0.90 / 1.25 for low, medium and high demand, and the
total split four ways.
What comes from the page
Every coefficient here is from the page: the ×10, the three factors, the
÷50, the four additions and their timings. The page doesn't state
Fermaid-O's YAN contribution in mg/L per g/L, so we don't compute one (see
TOSNA_GRAMS_PER_GALLON_PER_PPM). We treat Brix × 10 × factor as
the nitrogen target in ppm because that's what it is dimensionally, and the
page's guidance for it is 150–200 ppm.
Brix from gravity
The input is SG, like everything else in this package, and a mead maker
reads a hydrometer. sgToBrix does the conversion, and the Brix is
reported in the explanation so the result can be checked against the
published calculator using the same number.
A must with no volume, or at or below 1.000, needs no nutrient: the result
is zero grams across four zero additions, not a negative dose.
Fermaid-O for a must, split into TOSNA's four additions.
Honey has around 30 ppm of nitrogen, against the 150–200 ppm a healthy fermentation needs, which is why a mead fermented without nutrient can take a year to lose its sulphur. TOSNA (Sergio Moutela's Tailored Organic Staggered Nutrient Addition) sizes the dose from the must's sugar and the strain's demand, and staggers it so the nitrogen arrives while the yeast can still take it up.
The formula as published at https://www.meadmaderight.com/nutrient-additions:
with the factors 0.75 / 0.90 / 1.25 for low, medium and high demand, and the total split four ways.
What comes from the page
Every coefficient here is from the page: the ×10, the three factors, the ÷50, the four additions and their timings. The page doesn't state Fermaid-O's YAN contribution in mg/L per g/L, so we don't compute one (see TOSNA_GRAMS_PER_GALLON_PER_PPM). We treat
Brix × 10 × factoras the nitrogen target in ppm because that's what it is dimensionally, and the page's guidance for it is 150–200 ppm.Brix from gravity
The input is SG, like everything else in this package, and a mead maker reads a hydrometer. sgToBrix does the conversion, and the Brix is reported in the explanation so the result can be checked against the published calculator using the same number.
A must with no volume, or at or below 1.000, needs no nutrient: the result is zero grams across four zero additions, not a negative dose.