Sugar by solution mass
18°Bx = about 18% soluble solids by massGrape must contains acids and other solids, so it is not pure sucrose solution.
← All calculatorsBRIX TO SUGAR
Wine Sugar & Potential Alcohol Calculator
Raise a must from its current Brix to a target level and see the estimated sugar addition, gravity, and potential alcohol.
MORE THAN A SIMPLE DIFFERENCE
Added sugar also increases total mass
Simply multiplying the Brix difference by volume ignores the weight of the sugar addition. FermentWise estimates current must mass from Brix, then solves the concentration balance for the target.
Plan with a realistic factor
target Brix × 0.6Actual alcohol depends on fermentation efficiency and residual sugar.
COMMON QUESTIONS
Wine sugar calculator FAQ
How much sugar should I add to wine must?
Enter must volume, current Brix, and target Brix. The calculator uses a mass-balance estimate, accounting for the sugar already present and the mass added by new sugar.
What does Brix mean?
One degree Brix represents one gram of sucrose per 100 grams of solution under the scale’s reference conditions. Grape must also contains non-sugar soluble solids, so Brix is an approximation of fermentable sugar.
How is potential alcohol estimated?
FermentWise uses the UC Davis planning factor of Brix multiplied by 0.6. It is a potential value, not measured finished alcohol.
Can I use a refractometer after fermentation starts?
Not directly. Ethanol interferes with refractometer readings. Use an appropriate correction method or laboratory analysis for fermenting wine.
Research-based sources
- UC Davis Viticulture and Enology: Potential ethanol from Brix — the 0.6 planning factor and its limitations.
- Ontario Regulation 406/00 — legal definition of Brix as sucrose-equivalent dissolved solids by mass.
- Penn State Extension: Wine analytical laboratories — alcohol interference and the role of quantitative analysis.