Extraction Fundamentals
The Ratio: How Coffee to Water Defines Strength
The ratio of coffee to water is the first choice a brewer makes. It sets the strength of the cup before any other variable enters the conversation.
General guidelines, not hard rules, vary by extraction method. Pour-over filter methods like the V60 and Kalita Wave typically use ratios between 1:15 and 1:17, with 1:16 sitting as the most common starting point. The Chemex, with its thicker filter and slower extraction, often runs slightly stronger at 1:15 to 1:16. Immersion methods like the French press generally use 1:15 to 1:17, depending on steep time. AeroPress recipes range widely from 1:12 to 1:17 depending on whether the brewer is targeting concentration or filter-style clarity. Cold brew uses dramatically more concentrated ratios of 1:5 to 1:8 because the slow extraction at low temperature requires more coffee to produce comparable strength. Espresso uses the narrowest ratios of all, typically 1:2 to 1:3 for traditional preparations, because the method concentrates rather than dilutes. These are starting points rather than rules, and individual coffees, equipment, and preferences shift the targets in either direction.
Strength and extraction are related but distinct. Strength is the concentration of coffee in the cup — how much coffee per ounce of water made it through. Extraction is the percentage of the bean's soluble material that the water pulled out. A cup can be strong and still landing on the bright side of balance, or softer in strength and fully extracted. Each variable responds to different adjustments.
Ratio is the frame around which the other choices arrange themselves. Café de Volcán encourages drinkers to set their ratio deliberately, to taste the cup it produces, and to adjust with intention when they want to move toward something different. The ratio is the easiest variable to change between cups, and one of the most illuminating to explore.
