Winemaking Calculators

Sugar, acid, sulfite and blending numbers. 11 calculators for home and small-batch winemakers. Beer, cider and kombucha sit under Fermentation.

Sulfite addition is the one to read first, because the answer depends on pH far more than most people expect. Only a small fraction of free sulfur dioxide is the molecular form that actually protects the wine, and that fraction collapses as pH climbs. A red at pH 3.0 needs around 8 mg/L of free SO2 to hit the usual 0.5 target. The same wine at pH 3.8 needs about 49. That is a six-fold swing driven by a number many hobbyists never measure at all, and it is the strongest argument for fixing acid before worrying about sulfite.

Brix to potential alcohol offers a factor rather than baking one in. The chemical ceiling is about 0.607 if every sugar molecule converted perfectly, but yeast diverts some into glycerol and cell walls, so 0.55 is the figure to plan a wine around and 0.59 flatters your strain.

Residual sugar and chaptalization run on the same sugar model, so a wine planned on one lines up with the other.