Tools you might need next
Calculate blend ratios to achieve target ABV from liquids of different alcohol concentrations. Wine, spirits, and cocktail blending math.
Calculate number of bottles from batch volume for wine, beer, and spirits. Standard 750ml, 375ml, and 1L bottle yields with loss allowance.
Calculate classic cocktail ingredient ratios and scale recipes by serving count. Spirit, modifier, and mixer proportions for balanced drinks.
Potassium metabisulfite is 57% SO2 by weight. 1 g in 1 liter adds ~570 ppm SO2 (before binding).
1 g KMBS releases ~570 mg SO2At pH 3.2: 25 ppm free SO2 adequate. At pH 3.6: need 50 ppm. At pH 3.8: need 75+ ppm for same antimicrobial protection.
Target free SO2 increases with pH (molecular SO2 constant)Calculate ppm deficit, multiply by volume, divide by SO2 yield per gram KMBS.
KMBS (g) = (Target − Current) ppm × Volume (L) ÷ 570Updated: July 2026
pH 3.5, current free SO2 15 ppm, target 35 ppm: need 20 ppm addition → 0.7 g KMBS for the batch.
50 ppm SO2 on 100 kg crushed grapes (~75L juice): 6.6 g KMBS added at crush for antimicrobial protection.
One tablet ≈ 0.44 g KMBS ≈ 250 ppm SO2 per gallon. Calculate tablet count from KMBS gram equivalent.
Sulfur dioxide (SO2) protects wine from oxidation and microbial spoilage. Enter wine volume, current and target free SO2, pH, and product concentration to calculate potassium metabisulfite (KMBS) or Campden tablet additions.