In specialty coffee, "ratio" means how many kg of coffee you use per kg of water. Always noted as coffee : water. The global convention.

Why it matters

The ratio determines the concentration of the final beverage — how "strong" or "light" it turns out. Then, indirectly, it also influences extraction — how much of the coffee mass passes into the water.

Main conventions

  • 1:15 (15g coffee + 225g water) — strong, dense, closer to espresso. Used in concentrated techniques.
  • 1:16 (15g coffee + 240g water) — the modern V60 standard. Perfect balance.
  • 1:17 (15g coffee + 255g water) — lighter, more "watery." For very aromatically concentrated coffees (Geisha, Yemen).
  • 1:14 — AeroPress invert, fuller body.
  • 1:8 - 1:12 — Cold Brew (concentrated, diluted upon serving).
  • 1:2 — Espresso (18g coffee → 36g in cup).

How to decide the right ratio

For coffees with a sweet-round profile (Brazil, Honduras, Peru) — 1:16 ratio is perfect. It turns out balanced.

For bright-citric coffees (Ethiopia, Kenya, Tanzania) — 1:17 ratio allows the acidity to be elegant, not aggressive.

For bold-earthy coffees (Sumatra, Monsoon Malabar) — 1:15 or 1:14 ratio amplifies the body.

What happens from under-extraction to over-extraction

The ratio does NOT directly determine extraction. That is given by grind + temperature + time. But a lower ratio (less water) tends to yield "less extracted" coffees because there is less water to pass through the coffee.

This doesn't mean you always want more water. You want the ideal extraction (~20% of the coffee's mass) plus the concentration you like.

Practical example — same coffee, two ratios

Ethiopia Yirgacheffe Washed, 15g:

  • At 1:15 (225g water) — denser body, intense acidity, compressed aroma. Almost espresso-like.
  • At 1:17 (255g water) — delicate-elegant profile, clear jasmine, light body. "Classic" Yirgacheffe.

Neither is wrong. They are different experiences.

How to experiment systematically

  1. Fix grind, temperature, time.
  2. Make 1 cup at 1:15, one at 1:16, one at 1:17.
  3. Taste them when they reach 50°C (aromas are clearer when cooler).
  4. Note what you like.

Our calculator offers implicit ratios per method. You can adjust if you wish.

What is not calculated correctly

"Espresso 1:2" is an approximation. In reality, light roasts require 1:2.2 or 1:2.5, and dark roasts 1:1.5 — depending on how the coffee extracts.

See the Professional Barista course for espresso ratios per roast level.