Combine coarsely ground coffee with cold water at a 1:4 to 1:5 ratio, steep 12–24 hours, then strain and dilute 1:1 before serving.
A coarse grind and a long, cool soak separate smooth cold brew from a bitter, muddy glass. A tight 1:4 to 1:5 concentrate is diluted before drinking; a 1:8 to 1:15 batch pours straight over ice. Get those two numbers right and the rest is waiting. Pre-ground works fine; whole beans taste brighter, but the coarse setting matters more than the freshness date.
What Grind Size Does Cold Brew Need?
Coarse or medium-coarse — roughly the texture of raw sugar or coarse sea salt. Fine grounds are the biggest cause of cloudy, gritty cold brew. Cold water extracts slowly, so grounds sit for half a day or more. Fine particles give water more surface area and slip through most filters, producing over-extracted, bitter brew with sediment.
- Coarse: ideal for a French press, mason jar, or dedicated cold brew maker.
- Medium-coarse: works if your grinder can’t go truly coarse, but expect more sediment.
- Fine (espresso, drip): skip it. You’ll get sludge and bitterness.
With only fine pre-ground coffee, line your strainer with a paper filter or doubled cheesecloth. The cup will be less clear but drinkable.
How Long Should Cold Brew Steep?
Steep 12 to 24 hours, tasting at the 12-hour mark. Many coffees peak between 16 and 20 hours. A 12-hour steep gives a lighter, brighter concentrate; 20 hours pulls deeper, sweeter notes. Past 24 hours, the brew turns bitter and woody.
Add grounds to cold or room-temperature water in a covered jar or cold brew maker and let it sit on the counter or in the fridge. A fridge steep runs slower, so lean toward the longer end.
| Ratio (Coffee:Water) | Steep Time | How to Serve |
|---|---|---|
| 1:4 to 1:5 (concentrate) | 16–20 hours | Dilute 1:1 with water or milk |
| 1:8 (strong ready-to-drink) | 14–18 hours | Pour over ice, no dilution |
| 1:10 (medium) | 12–16 hours | Serve straight, light ice |
| 1:15 (mild) | 12 hours | Drink as-is, chilled |
| 1:5, fridge-steeped | 20–24 hours | Dilute 1:1, taste first |
Straining, Diluting, and Storing
Strain through a fine-mesh sieve, paper filter, or your maker’s built-in filter, then dilute concentrate 1:1 with water or milk. A quick pour through a coarse strainer leaves fine silt. For a clear cup, strain twice: mesh first, then paper or cheesecloth.
Undiluted concentrate is roughly four to five times stronger than regular coffee — pour 1:1 with water, milk, or a milk alternative over ice, taste, and adjust toward 1:2 for a milder glass. Store strained brew covered in the fridge. No official shelf life exists for homemade cold brew; when it tastes flat or sharp, it’s done. A few days is a reasonable window, and concentrate holds longer than a diluted batch.
To skip the grind-size guesswork, our roundup of the best cold brew ground coffee to buy covers blends ground for this method.
- Too bitter? Your grind was too fine, or you steeped past 24 hours.
- Too weak? Steep longer before adding more coffee — extraction usually beats ratio.
- Cloudy or gritty? Filter again through paper, and grind coarser next time.
FAQs
Can I use regular pre-ground coffee instead of coarse?
Yes, with extra filtration. Standard drip grind is finer than ideal, releasing more sediment and leaning bitter over a long steep. Line your strainer with a paper filter or doubled cheesecloth, taste at 12 hours rather than 20, and expect a cloudier cup.
Should I steep cold brew in the fridge or on the counter?
Either works, at different speeds. A countertop steep extracts faster — 12 to 16 hours is plenty. A fridge steep is slower and more forgiving, so 20 to 24 hours won’t turn harsh, and it keeps flavor cleaner if you forget about it.
Do I have to dilute cold brew concentrate?
Yes, in most recipes. A 1:4 or 1:5 concentrate is roughly four to five times stronger than regular coffee, so straight drinking tastes overpowering. Pour 1:1 with cold water or milk over ice, taste, then adjust toward 1:2 for milder. Ready-to-drink batches at 1:8 to 1:15 pour as-is.
References & Sources
- Wikipedia. “Cold brew coffee.” Confirms the cool-water steeping definition and extended brew times.
- Equator Coffees. “How Long to Steep Cold Brew.” Supports the 12–24 hour window and the 16–20 hour sweet spot.