Brix to Potential Alcohol Calculator
Convert grape juice Brix (sugar content) to potential alcohol percentage.
Essential for winemaking planning and harvest decisions.
Brix (°Bx) measures the percentage of dissolved sugars in grape juice. It is the primary tool winemakers use to decide when to harvest and to predict the final alcohol content of wine.
Conversion formula: Potential ABV ≈ Brix × 0.55 to 0.59
The conversion factor varies because yeast efficiency, grape variety, and fermentation conditions affect sugar-to-alcohol conversion. A conservative estimate uses 0.55; most practical winemaking uses 0.55–0.57. The theoretical maximum (complete conversion) is about 0.607.
Harvest timing by Brix:
- Under 20°Bx: Too early — low alcohol, high acidity, under-ripe flavors
- 20–22°Bx: Early harvest style — crisp whites, sparkling wine base
- 22–24°Bx: Ideal for most white wines (11–14% ABV)
- 24–26°Bx: Ideal for most red wines (13–15% ABV)
- 26–28°Bx: Rich, full-bodied style — risk of stuck fermentation without nutrients
- Over 28°Bx: Dessert wine territory — may not fully ferment dry
Measurement tools: Refractometer (quick field use), hydrometer (lab precision). Refractometers must be corrected for alcohol in finished wine — use the Brix-only reading on fresh juice before fermentation.
Potential alcohol vs actual: These formulas give potential alcohol assuming complete fermentation. Some sugar may remain (residual sugar) in sweet wines, or fermentation may stop early (stuck fermentation), resulting in lower actual ABV.