Brew ratio

The ratio of dose (dry ground coffee, by weight) to yield (brewed espresso, by weight). For example, 18 g in, 36 g out is a 1:2 ratio. Sometimes also called yield ratio or output ratio.

Why it matters — Brew ratio is the single most useful number for dialling in. It tells you whether you're pulling a short, intense shot or a long, lighter one — independent of grind size or shot time.

Good to know

• Standard espresso: 1:2. Ristretto: 1:1 to 1:1.5. Lungo: 1:2.5 to 1:3.
• Modern light-roast "turbo" shots often run 1:2.5 to 1:3 in 15–20 seconds — same yield ratio, very different extraction approach to traditional espresso.