Weigh dose in and yield out at the machine — this tool tells you exactly which ratio you pulled and what to change for a target ratio.
An espresso brew ratio is dose : yield — grams of dry coffee in versus grams of liquid espresso out. The ratio determines the style of the shot: ristrettos (around 1:1.5) are dense and syrupy, normales (1:2) are the modern default, and lungos (1:2.5–1:3) are longer and more extracted. Formula: ratio = yield ÷ dose.
Yes — crema is part of the liquid espresso and is included in the standard weighed yield.
Volume is unreliable because crema density varies. Weight gives you a stable, repeatable number.
1:2 is the modern default across most coffees and machines. Move to 1:2.5 for delicate light roasts, 1:1.5 for dense dark roasts.
Bitterness with correct ratio usually means over-extraction. Grind coarser, lower temperature by 1–2°C, or shorten the shot slightly.