The short answer: to make cold brew coffee, stir 100 g of coarsely ground coffee into 400 ml of cold water. Cover it and leave it for 12 to 24 hours. Strain it through a paper filter, then mix 1 part concentrate with 1 part water or milk over ice. Keep it in the fridge and drink it within 1 week.
Cold brew coffee is coffee steeped in cold water for hours instead of hot water for minutes. Cold water pulls out flavour slowly. You get a smooth, round cup that tastes of chocolate and nuts, with little of the sharp edge of hot coffee poured over ice. It costs ten minutes of work and one night of waiting.
| At a glance | |
|---|---|
| Hands-on time | 10 minutes |
| Steeping | 12 to 24 hours |
| Ratio | 1:4 coffee to water for concentrate, then 1:1 to serve |
| Keeps | Up to 1 week in the fridge |
What you need
- 100 g (about 1 cup) coffee beans, medium or dark roast
- 400 ml (1⅔ cups) cold filtered water
- A jar or French press of at least 600 ml
- A sieve and a paper coffee filter, or a clean cloth
Grind the beans coarse, like raw sugar or breadcrumbs. Fine coffee turns muddy, clogs the filter and tastes bitter after a long steep. Pre-ground coffee for filter machines works, but it is on the fine side, so keep the steep near 12 hours.
How to make cold brew coffee
- Grind. Grind 100 g of beans on a coarse setting.
- Stir. Put the coffee in the jar, pour in 400 ml of cold water and stir until there are no dry clumps.
- Steep. Cover the jar and leave it for 12 to 24 hours. America's Test Kitchen steeps its concentrate on the counter for 24 hours. You can steep it in the fridge too; it is slower, so give it the full 24.
- Strain twice. Pour it through a sieve to catch the grounds. Then pour it again through a paper filter to catch the fine silt. Do not squeeze the grounds.
- Chill and serve. Bottle the concentrate and keep it in the fridge. To serve, mix 1 part concentrate with 1 part cold water or milk over ice.
The ratio, and how to change it
A 1:4 concentrate is easy to dilute to taste. Change the water, not the steep time, if you want a lighter or bolder cup.
| Goal | Coffee : water | How to serve |
|---|---|---|
| Concentrate | 1:4 | Mix 1:1 with water or milk |
| Ready to drink | 1:8 | Pour straight over ice |
| Latte style | 1:4 | 1 part concentrate to 2 parts milk |
| Hot cold brew | 1:4 | Mix 1:1 with just-boiled water |
The ready-to-drink version takes up twice the fridge space for the same number of glasses. That is why most people brew a concentrate.
Which coffee to use
Medium and dark roasts give the classic cold brew taste: cocoa, caramel, toasted nuts. Light roasts work too, but the fruity, floral notes come through quieter than in a hot brew. Fresh beans matter more than the brand. Buy them whole and grind them just before you start.
How to flavour cold brew
Cold brew is a blank canvas for syrups. Add 1 to 2 teaspoons per glass and stir before the ice goes in, so it mixes.
- Vanilla: our vanilla syrup with oat milk is the café classic.
- Cinnamon: a spoon of cinnamon syrup and a splash of cream.
- Brown sugar: brown sugar syrup gives a toffee taste that suits dark roasts.
- Spices in the steep: add 1 cinnamon stick or 3 crushed cardamom pods to the jar with the coffee. Strain them out with the grounds.
- Cold brew ice cubes: freeze some concentrate in an ice-cube tray. The drink does not go watery as they melt.
How long cold brew keeps
- Concentrate in the fridge: up to 1 week, in a clean jar with a tight lid. America's Test Kitchen gives the same time.
- Diluted cold brew: mix only what you will drink that day.
- With milk: drink it straight away. Do not store cold brew once milk is in it.
- At room temperature: only during the steep. Once strained, it goes into the fridge.
Write the date on the jar. After a week the taste turns flat and stale even when it looks fine. Throw it out if it smells sour or shows anything floating on top.
Common mistakes
- A fine grind: it over-extracts and turns bitter, and the filter clogs. Grind coarse.
- Steeping too long: after about 24 hours the coffee picks up woody, bitter notes. Set a timer.
- Squeezing the grounds: it pushes silt and bitterness into the jar. Let it drip.
- One quick strain: a sieve alone leaves sludge at the bottom of every glass. Strain a second time through paper.
- Drinking the concentrate neat: it is twice as concentrated as the glass you serve. Dilute it.
Questions
What is the best ratio for cold brew coffee?
Use 1 part coarse coffee to 4 parts cold water by weight for a concentrate, such as 100 g of coffee to 400 ml of water. Mix it 1:1 with water or milk to serve. For a ready-to-drink batch, use 1 part coffee to 8 parts water.
How long should cold brew steep?
Steep it for 12 to 24 hours. 12 hours gives a lighter cup; 24 hours gives more body. Past 24 hours, the coffee starts to taste woody and bitter.
How long does cold brew coffee last in the fridge?
Up to 1 week for the strained concentrate, in a clean jar with a tight lid. Once you add milk, drink it the same day.
Can I use regular ground coffee for cold brew?
Yes, but it is finer than ideal. Steep it for about 12 hours, not 24, and strain it through a paper filter so the glass stays clear.
Can I heat up cold brew?
Yes. Mix the concentrate 1:1 with just-boiled water. It tastes smoother than coffee brewed hot.
