Brew Ratio
Brew ratio is the proportion of ground coffee to liquid water, typically expressed as grams of coffee per grams (or millilitres) of water. Espresso standard: 1:2 (18 g coffee to 36 g liquid in 25-30 seconds). Filter coffee SCA Golden Cup: 55 g/litre (approximately 1:15-1:18). Ristretto: 1:1 to 1:1.5. Lungo: 1:3 to 1:4. Ratio is one of the primary extraction variables alongside grind size, water temperature, and contact time. Tracking ratio by weight (using a scale) is essential for reproducible results.
Background & Context
The water-to-coffee ratio (ratio eau:café) is the fundamental brewing parameter that determines the strength (concentration) of the final brew — expressed as the mass of water divided by the mass of coffee. The SCA Brewing Control Chart specifies an ideal ratio range of 55–65 grams of coffee per litre of water (1:15.4 to 1:18.2) for filter coffee. Espresso uses dramatically more concentrated ratios: typically 2:1 to 3:1 (water:coffee by weight, yielding 1:2 or 1:3 in coffee-to-yield terminology). The ratio determines TDS (Total Dissolved Solids) and thus perceived strength — but not extraction yield (EY), which is a function of contact time, temperature, and grind size. Two brews at identical ratio but different grind sizes can have the same TDS but different EY — one correctly extracted, one under-extracted but underpowered by coarse grind.
Practical Use
Practical ratio management: for filter coffee, start at 1:15 (67g/litre) as a baseline and adjust to taste. If the brew tastes too weak (thin, watery), reduce ratio (more coffee: 1:14 or 1:13). If too strong (thick, overwhelming), increase ratio (less coffee: 1:16 or 1:17). The SCA "ideal zone" (1:15.4–1:18.2) is statistically derived from consumer preference studies — many specialty drinkers prefer ratios outside this zone. For espresso, the most common specialty starting point is 1:2 (18g in, 36g out) but light-roasted single-origins often perform better at 1:2.5–1:3. Keeping dose fixed and adjusting yield weight is the most controlled method for exploring the ratio's flavour effects.
Related Terms
Related terms: Brew ratio, TDS, Brewing control chart, Espresso extraction, Dose.