Wine making
Chaptalization calculator.
Enter the current and desired reading of your must and the batch size to see how much sugar to add.
Inputs
Sugar to add
Enter your numbers.
How it works
Chaptalization is adding sugar to unfermented must so the yeast has more to ferment into alcohol. It is not meant to make the wine sweeter. Brewer’s Friend gives the working rule this tool uses: to raise 1 gallon of must by 1 Brix, add 1.5 oz of sugar. If you enter specific gravity, it is converted to Brix first.
Worked example. Five gallons of must reads 20 Brix and you want 23. That is a rise of 3 Brix, so the sugar is 3 × 1.5 oz × 5 gal = 22.5 oz, which is 638 g or 1.41 lb. The potential alcohol rises from 10.9% to 12.7%, using ABV = (OG − 1.000) × 131.25.
Dissolve the sugar in a little warm must and stir it back in, since sugar added dry sinks and is hard to measure. Wikipedia notes that the legality of chaptalization varies by country, region and even wine type, and gives Alsace Riesling grapes that have not fully ripened as an example of its use. If you make wine commercially, check the rules where you operate. Do not overshoot: very high alcohol can stress yeast.
Frequently asked questions
How much sugar raises Brix by 1 degree?
Brewer's Friend states that 1.5 oz of sugar raises 1 gallon of must by 1 Brix. That is about 42.5 g per gallon.
Does the volume I enter include the sugar?
Enter the expected volume of the finished must. Brewer's Friend advises using the expected wine volume rather than the volume you start with.
Is chaptalization legal?
Wikipedia says its legality varies by country, region and even wine type. Rules vary by place, so check your local regulations.
Does adding sugar make the wine sweet?
No. The sugar is there for the yeast to ferment into alcohol. A wine is sweet only if fermentation stops with sugar left over.
Sources
Opened
- Brewer's Friend: Chaptalization Calculator: States that to raise 1 gallon of must by 1 Brix you add 1.5 oz of sugar, and to enter expected wine volume.
- Brewer's Friend: Brix Converter: Brix and specific gravity conversion equations.
- Brewer's Friend: ABV Calculator: Standard formula ABV = (OG - FG) x 131.25.
- Wikipedia: Chaptalization: Defines chaptalization and says its legality varies by country, region and wine type.
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Scope
Planning estimates. Real sugar adds slightly more volume and gravity varies with temperature, so confirm with a hydrometer. Rules on adding sugar to wine and on home alcohol production vary by jurisdiction. Not professional or legal advice.