Perfect carbonation for bottle-conditioned beer.
Bottle conditioning carbonates beer by adding a measured amount of fermentable sugar before capping. Residual yeast in the beer ferments the sugar, producing CO2 that dissolves into the beer under pressure. The key variable: residual CO2 already dissolved from fermentation (higher fermentation temperature = less residual CO2). For 2.4 volumes of CO2 (typical American ale) at 20°C, you need approximately 120g corn sugar (dextrose) per 19L batch. Too much sugar causes dangerous over-carbonation (bottle bombs). Always boil priming sugar in 500mL water and add to the bottling bucket evenly. Allow 2-3 weeks at 18-22°C for complete carbonation. Different sugars have different fermentabilities: dextrose is the baseline (100%), table sugar is 91% equivalent, DME needs 47% more by weight.