Coffee Brew Ratio Recipe Generator

Coffee brew ratios: the single number that separates a watery cup from a balanced one

A brew ratio is the ratio of dry coffee grams to brewing water (also in grams, since 1 mL of water at room temperature weighs 1 g). It is the most influential variable in extraction — more than grind size, water temperature or even bean origin — because it sets the maximum solubles available per millilitre of cup. The SCA (Specialty Coffee Association) calls 1:18 the "Golden Ratio" — about 55 g of coffee per 1 L of water — landing the cup in the 18–22% extraction window with a TDS between 1.15 % and 1.35 %.

Each method has its own canonical range:

• Espresso: 1:2 modern (18 g in, 36 g out); 1:1.6 ristretto; 1:3 lungo.
• Pour-over (V60, Chemex, Kalita): 1:15 to 1:17.
• French press: 1:12 to 1:15 — heavier body from full immersion.
• AeroPress: 1:13 standard, both regular and inverted methods.
• Cold brew concentrate: 1:8, then dilute 1:1 with water/milk.
• Drip coffee maker: 1:15 to 1:18.

Variables that move the cup

Ratio is the starting point, not the whole story. Grind size changes contact area: espresso is fine like granulated sugar, V60 like sea salt, French press like kosher salt, cold brew like rough crystals. Water temperature sits at 90–96 °C for hot methods (espresso targets 92–96 °C at 9 bar pressure). Time matters — 2–4 min for V60, 4 min French press plunge, 25–30 s espresso shot, 12–24 h cold brew. Lighter roasts need higher ratios (more coffee) and finer grinds to push extraction; darker roasts go the opposite way to avoid burnt bitterness.

TDS, refractometers and the third wave

TDS (Total Dissolved Solids) measures the strength of the brew. A VST refractometer reads TDS optically and lets baristas iterate: 1.15–1.45 % is the standard espresso window; 1.15–1.35 % for filter. The third-wave coffee movement (2010s onward) made single-origin, traceable beans and competition-grade equipment mainstream; the WBC (World Barista Championship) runs annually. Brewing icons include the V60 from Hario (Japan), the Chemex by Peter Schlumbohm (1941) and the AeroPress by Alan Adler (Aerobie, 2005). Brazil is the world's largest coffee producer (~40 %) and famous roasters include Suplicy, Octavio Café, Coffee Lab (Isabela Raposeiras) and Wolff.

Workflow with the calculator

Method: V60
Coffee: 20 g
Ratio: 1:16
Water:  320 g
Bloom:  40 g for 30 s, then continue
Time:   2:30 – 3:15

Pour the bloom (twice the coffee weight in water), wait 30 s, then continue in two or three pulses. Use a smart scale like Acaia Pearl or the Brewbox app to track time and weight together.

FAQ

Best method for a beginner? A simple V60 — cheap dripper, paper filter, predictable flow. Pair it with a burr grinder (blade grinders are unevenly chopped and ruin specialty beans).

Does freshness matter? Yes. Specialty coffee peaks 5–21 days after roast; after 4–6 weeks aromas flatten. Buy beans whole, store airtight, away from light and heat.

Is a refractometer worth it? Only if you brew daily and want repeatable results. For most home setups a scale plus the calculator above is enough.

Can I use volume instead of grams? You can, but a scoop of beans varies 30 % in weight by roast and size. A scale is the cheapest upgrade in specialty coffee.