Slow Pour brew guide
Coffee to water ratio calculator
For most filter coffee use 1 g of coffee for every 15 to 17 g of water: about 15 g of coffee for a 250 ml mug. Pick a stronger ratio (1:15) for a bolder cup or a lighter one (1:17) for a softer cup.
Ratio calculator
How the ratio works
A ratio of 1:16 means 16 grams of water for every gram of coffee. Multiply your coffee by the ratio to get the water, or divide the water by the ratio to get the coffee. Grams of water and millilitres are the same, so a 250 ml mug needs 250 g of water.
Common ratios
- Pour-over and drip: 1:15 to 1:17
- French press and other immersion: 1:15 to 1:17
- AeroPress: about 1:15, or stronger to dilute
- Moka pot: about 1:9, set by the size of the pot
- Cold brew concentrate: 1:8, then dilute about half and half
- Espresso: about 1:2 (grams of coffee out, not water in)
Worked examples
- One mug of 250 g water at 1:16.7: 250 ÷ 16.7 = 15 g of coffee
- Two mugs of 500 g water at 1:16: 500 ÷ 16 = 31 g of coffee
- A litre of cold brew concentrate at 1:8: 1000 ÷ 8 = 125 g of coffee
Strength isn’t the same as extraction
The ratio decides how strong the cup is. Whether it tastes sour or bitter is mostly the grind, the temperature and the time. If a cup is weak and sour, grind finer; if it’s just weak, use more coffee.
Questions
How many grams of coffee per cup?
About 15 g for a 250 ml mug at a classic 1:16.7. That’s roughly two level tablespoons of whole beans, but weighing is far more reliable.
What is the golden ratio for coffee?
The Specialty Coffee Association’s guideline works out at about 55 g of coffee a litre, close to 1:18, for drip coffee. Most home brewers go a little stronger, 1:15 to 1:17.
Does the ratio change for more cups?
No, keep the ratio and scale both numbers. A bigger brew drains more slowly, so you may want a slightly coarser grind.