Sugar Wash Calculator

Sugar → ABV: Enter your wash volume and the amount of sugar you plan to use. The calculator tells you the potential ABV you can expect after full fermentation, along with the starting gravity (OG) and estimated final gravity (FG).

ABV → Sugar: Know your target wash strength? Enter the volume and target ABV and the calculator works backwards to tell you exactly how much sugar to add.

SG / Brix: Already have a hydrometer or refractometer reading? Enter your SG (e.g. 1.080) or Brix (e.g. 20.5°Bx) directly. The calculator converts using the ICUMSA polynomial for accurate Brix-to-SG conversion, then applies sucrose fermentation stoichiometry for potential ABV.

Specific Gravity and Brix are related but not linearly. The ICUMSA polynomial gives an accurate conversion:

For potential ABV, the simplified formula (OG − 1) × 131.25 is fine for quick estimates at beer-strength gravities. For sugar washes, this calculator uses fermentation stoichiometry instead, because it stays physically correct at any gravity:

The 0.538 comes from sucrose chemistry: each gram hydrolyses to 1.0526 g of invert sugar, and fermentation converts 51.1% of that mass to ethanol. This puts a hard ceiling of about 6.8% ABV per 100 g/L of sugar at perfect conversion. Beer-wort formulas such as Balling are calibrated for malt extract below roughly 1.12 OG and give physically impossible answers when pushed to sugar-wash gravities, which is why they are not used here.

75% — Cold temperature, no nutrients, stressed yeast, or wash above 20% potential ABV.

85% — Typical home distilling with basic yeast nutrients. Safe default for most washes.

90% — Good conditions: proper nutrients (DAP + Fermaid), 25–30°C, healthy pitch rate.

95% — Optimised turbo or dedicated distilling yeast with full nutrient protocol.