Homebrewing chemistry

Hardness and chlorine are the main flavor enemies. Let it stand/boil or filter. Soft water for light styles, harder for stouts.

OG (original) and FG (final) gravity via hydrometer. ABV ≈ (OG − FG) × 131.25. Typical: OG 1.040–1.060, FG 1.008–1.015.

62–65°C — sweet body (β-amylase), 68–72°C — drier (α-amylase). Mash pH 5.2–5.6 — acidity drives the enzymes.

Fermentation temperature is critical: ale 18–22°C, lager 8–14°C. Overheating — esters and fusels. Rehydrate dry yeast in 25°C water for 15 min.

90% of failed beer is infection from dirt. Iodophor/peroxide on everything touching post-boil wort. Cleaning ≠ sanitizing.

Priming sugar: 6–8 g/L for medium carbonation. Overdosing — bottle bombs. Kegs — CO₂ via pressure-temperature charts.