Fermentation mathematics

Must is freshly crushed grape juice with skins, seeds, and sometimes stems before or during fermentation. Yeast converts fermentable sugars primarily into ethanol and carbon dioxide while also producing heat and many secondary compounds.

Hydrometers infer density; refractometers infer dissolved-solids concentration from light bending. Potential-alcohol estimates depend on measurement method, conversion factors, and fermentation completion.

The headline conversion from sugar to ethanol and carbon dioxide is chemically useful, but real fermentation also produces biomass, heat, glycerol, acids, aroma compounds, and other products. Yeast strain, nutrients, temperature, oxygen history, inhibition, and sugar composition affect the realised outcome.

A potential-alcohol estimate depends on how sugar or density was measured, the conversion factor used, temperature correction, and whether fermentation reaches dryness. It is a planning estimate, not a guarantee. Comparing estimates responsibly requires the same units, methods, and assumptions.

Calculate potential alcohol from one must value using two plausible published conversion factors. Report both estimates, the difference, and the assumptions. Then write the operational decision the estimate might support. This turns arithmetic into evidence-aware cellar reasoning rather than false precision.