Ratio for a drinkable batch
Ready-to-drink cold brew runs about 1:12, so 83 g of coffee for 1 liter of water. Roasters land between 1:11 and 1:13. A hot cup uses less coffee, at 1:15 to 1:17. Pour this one straight over ice. Want it stronger? Add more coffee next time. Steeping longer will not help. A concentrate is a different ratio, and it has its own page.
Grind and steep time
Grind coarse, about like rock salt. Fine grounds make the brew bitter, cloudy and gritty. One roaster grinds a notch finer for a fuller feel, so medium-coarse also works. Under 12 hours tastes light and tea-like. Past 24 hours it can turn bitter. Sixteen hours is a safe middle for most coffee.
| 500 ml jar | 1 L jar | 1.9 L jar | |
|---|---|---|---|
| Water | 500 g, 17 oz | 1,000 g, 34 oz | 1,900 g, 64 oz |
| Coffee at 1 : 12 | 42 g | 83 g | 158 g |
| You pour off, about | 420-440 g | 830-875 g | 1,580-1,660 g |
The jar method
Weigh the coffee into a clean jar. Pour in half the water and stir, then add the rest, so no dry pockets stay. Put the lid on. Leave the jar on the counter, out of the sun, for 12 to 16 hours. In the fridge, give it 18 to 24. Start tonight and you have a glass by breakfast.
Straining it clean
Strain right when the time is up, because coffee left on the grounds keeps brewing. Pour through a fine mesh strainer first, then through a paper filter or cheesecloth. Paper gives a cleaner cup, and cloth leaves more body. Rinse paper filters first. Or skip straining: steep the coffee in a filter bag and lift it out, as the National Coffee Association describes.
Serving and keeping
Pour over ice and add water or milk to taste. Freeze leftover cold brew into cubes, and the glass stays strong as they melt. Add milk and sweetener at the glass, not the bottle. Keep the rest sealed in the fridge for about 3 to 5 days. Roasters say anywhere from 2 to 7. Toss it if it smells sour.