Chaptalisation calculator
Adding sugar to must raises the potential alcohol. Roughly 17 grams of sugar per litre yields one percent of alcohol.
%
g/L
Sugar to add
955g
- Sugar per litre
- 47.8 g/L
- Potential alcohol as it stands
- 10.19 %
- Alcohol to make up
- 2.81 %
- Gravity after the addition
- 1.0957
- Volume the sugar adds
- 0.597
- Final must volume
- 20.60
- Current sugar content
- 18.20 Brix
Show the working
- Must volume = 20
- Current specific gravity = 1.075
- Target alcohol = 13
- Sugar per percent of alcohol = 17
- Potential alcohol as it stands = (1.075 - 1) * 1000 / 7.36 = 10.1902
- Alcohol to make up = max(13 - 10.1902, 0) = 2.809 78
- Sugar per litre = 2.809 78 * 17 = 47.7663
- Sugar to add = 47.7663 * 20 = 955.326
- Volume the sugar adds = 955.326 * 0.625 / 1000 = 0.597 079
- Final must volume = 20 + 0.597 079 = 20.5971
- Gravity after the addition = 1 + (10.1902 + 2.809 78) * 7.36 / 1000 = 1.095 68
- Current sugar content = (((182.4601 * 1.075 - 775.6821) * 1.075 + 1262.7794) * 1.075 - 669.5622) = 18.1976
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- potential alcohol = gravity points / 7.36
- about 17 g of sugar per litre gives one percent of alcohol by volume
Chaptalisation is restricted or banned in some wine regions. Check the rules where you are before doing it commercially.
Sugar occupies volume, so adding it dilutes acidity slightly as well as raising alcohol.