Rye
Kitchen calculators
Baker’s math for sourdough, alcohol by volume from a hydrometer or a refractometer, a quantity list for a party, and a coffee-to-water ratio.
Sourdough Calculator
Sourdough hydration calculator using baker’s percentages. Flour, water, starter, and salt, with the starter’s flour counted in the total.
ABV Calculator
ABV calculator from original and final gravity, with the standard and alternate formulas and a refractometer correction.
Specific Gravity Calculator
Gravity calculator for hydrometer temperature correction, Brix to specific gravity, and a refractometer with alcohol correction.
Wedding Alcohol Calculator
Beer, wine, and liquor quantities for a guest list. A planning count only. Not a blood-alcohol calculator.
Coffee Ratio Calculator
Coffee-to-water ratio, grams per litre, and brewed yield. Golden Cup is the sourced starting point. Taste decides. No caffeine claim.
How these calculators work
Every sourdough ingredient is a percent of total flour. Total flour includes the flour inside the starter, so a 20% starter on 500 grams of flour is 100 grams of starter, and a 100% hydration starter is 50 grams of that flour. The water you pour is what’s left after the starter’s water is counted. A country loaf at 75% hydration, 20% starter, and 2% salt is the default.
ABV from a hydrometer is (OG − FG) × 131.25. The alternate formula, (76.08 × (OG − FG) / (1.775 − OG)) × (FG / 0.794), sits beside it because the two diverge as the beer gets stronger. A refractometer reading of finished beer needs a correction: this page uses Sean Terrill’s 2011 cubic, with a wort correction factor that defaults to 1.04. The specific gravity calculator corrects a hydrometer for temperature with Hall’s 1995 cubic, converts Brix, and calls that same refractometer correction. Specific gravity has no imperial or metric form. Temperature does. The wedding page counts bottles for a guest list. It is not a blood-alcohol tool. The coffee page is a brew ratio. The SCAA Golden Cup figure is 55 g per litre, and taste still decides.