Brewing & Distilling Converter
By KAMP Inc. / UnitOwl · Last reviewed:
Brewing and distilling rely on precise measurements of volume, gravity, temperature, and concentration to produce consistent results. From homebrewers converting between US and metric volumes to professional distillers calculating alcohol content, unit conversions appear at every step. The key quantities — specific gravity, ABV, degrees Brix, and Plato — each measure sugar or alcohol concentration in slightly different ways, and knowing how they relate prevents costly formulation errors.
Popular Brewing & Distilling Conversions
Specific Gravity, Brix, and Plato
Specific gravity (SG) measures the density of a liquid relative to water (water = 1.000). A sugar-heavy wort before fermentation might read 1.050 SG; as yeast convert sugars to alcohol, SG drops. Original gravity (OG) and final gravity (FG) bracket the fermentation. Degrees Plato (°P) expresses the weight percentage of sucrose equivalent in solution: 1°P ≈ 4 grams of sugar per 100 grams of wort. The relationship between SG and Plato: °P ≈ (SG − 1) × 250 (rough) or more precisely °P = 135.997 × SG³ − 630.272 × SG² + 1,111.14 × SG − 616.868. Degrees Brix (°Bx) is nearly identical to Plato and is used in wine and juice fermentation. A grape juice at 24 °Bx will yield roughly 13–14% ABV wine after full fermentation.
| Measurement | Equivalent |
|---|---|
| SG 1.040 | ~10 °Plato / 10 °Brix |
| SG 1.050 | ~12.4 °Plato |
| SG 1.060 | ~14.7 °Plato |
| SG 1.080 | ~19.3 °Plato |
| 1 °Plato | ≈ SG + 0.004 |
| Water (reference) | SG 1.000 / 0 °Plato |
Calculating Alcohol Content (ABV)
Alcohol by volume (ABV) is the standard measure of alcohol content worldwide. The simplified formula used by most homebrewers is: ABV = (OG − FG) × 131.25. For a beer with OG = 1.055 and FG = 1.010: ABV = (1.055 − 1.010) × 131.25 = 0.045 × 131.25 ≈ 5.9%. This formula is accurate within ±0.5% for beers under 8% ABV. For higher-gravity fermentations, the more accurate formula is: ABV = (76.08 × (OG − FG) / (1.775 − OG)) × (FG / 0.794). Proof (US) is simply ABV × 2: a 40% ABV spirit is 80 proof. UK proof historically used a different scale (57.15% ABV = 100 UK proof), but the UK now also uses ABV.
Volume Conversions in the Brewery
Homebrewing in the US uses gallons (typically 5-gallon batches); craft breweries use barrels (US barrel = 31 gallons = 117.3 liters) and hectoliters (HL). One hectoliter = 100 liters = 26.4 US gallons. Commercial breweries report production in barrels: a 1,000 barrel/year microbrewery produces about 117,000 liters annually. US fluid ounces are used for serving sizes (12 oz = 355 mL; 16 oz pint = 473 mL; imperial pint = 568 mL). For distilling, wash volumes are typically in gallons or liters, while yield is often discussed in proof gallons (a proof gallon is one gallon of 100-proof / 50% ABV spirit, regardless of actual volume). Temperature for fermentation and mashing is critical: most ale yeasts ferment between 18–22°C (64–72°F).
Sources & References
- NIST — Units and Conversion Factors — Official unit conversion factors from the National Institute of Standards and Technology.
- BIPM — The International System of Units (SI) — International SI unit definitions from the International Bureau of Weights and Measures.