How to Make Cold Brew at Home
Cold brew has a reputation for needing a $40 dedicated brewer sitting on your counter. It doesn’t. Cold brew is coarsely-ground coffee steeped in cold or room-temperature water for half a day or more — a jar, a strainer, and time is the entire equipment list. Here’s the actual method, the ratios that matter, and why it tastes nothing like iced coffee even though they look identical in a glass.
What Cold Brew Actually Is (and How It’s Different From Iced Coffee)
Cold brew is coffee extracted using only cold or room-temperature water, over a long time — no heat touches it at any point in the process. Iced coffee is regular hot-brewed coffee (drip, pour-over, whatever) that gets cooled or poured over ice afterward. It was a hot brew first; the “iced” part happens after the fact.
That difference matters for how it tastes, not just how it’s served. Heat pulls certain acidic and oil compounds out of coffee quickly. Cold water pulls those same compounds out far more slowly and in smaller amounts, even over many more hours of contact time. The result is a cup that’s naturally smoother and less acidic — even at a much higher concentration than a normal cup of coffee. Brew the exact same beans hot and pour them over ice, and you get a genuinely different, more acidic drink. Same beans, different process, different result.
The Method — Coarse Grind + Long Steep
- Grind coarse. Coarser than you’d use for drip — think coarse sea salt. Too fine and the steep turns muddy, gets hard to strain, and over-extracts into bitterness.
- Combine grounds and cold or room-temperature water in a jar or pitcher, at the ratio you’re targeting (below).
- Stir briefly to make sure every ground is saturated, then cover.
- Steep 12 to 24 hours — room temperature on the shorter end (12-16 hours), fridge on the longer end (18-24 hours), since cold slows extraction further.
- Strain twice. A fine mesh strainer catches the bulk of the grounds; a second pass through a coffee filter, cheesecloth, or a nut-milk bag catches the fine, silty sediment a mesh strainer alone lets through.
- What’s left is cold brew concentrate — store it and dilute to taste when you actually drink it, not before.
Getting the Ratio Right: Concentrate vs. Ready-to-Drink
Two target ratios, both by weight (coffee to water):
- Concentrate — about 1:4. Roughly 1 cup (about 3oz / 85g) coarse grounds to 4 cups (32oz) cold water. This is intentionally strong — meant to be diluted before drinking, not sipped straight.
- Ready-to-drink — about 1:8, roughly half the strength of concentrate. You can get there two ways: steep at a 1:8 ratio from the start (more water, same grounds), or steep concentrate at 1:4 and dilute the finished product roughly 1:1 with water, milk, or ice when you serve it.
Most people are better off making concentrate and diluting per glass — it’s more flexible (adjust strength to your mood or the drink) and the concentrate keeps well, so you’re not re-steeping every single day.
If you want to know your concentrate’s exact strength instead of eyeballing dilution, see Do You Need a TDS Meter? — this is the one place in home coffee where that number actually earns its keep.
Equipment — A Jar Works Just Fine
- A mason jar or any pitcher with a lid — $0 if you already own one.
- A fine mesh strainer you probably already own, for the first pass.
- Cheesecloth, an unbleached coffee filter, or a $5-10 nut-milk bag for the second, finer strain.
- A dedicated cold-brew maker — a pitcher with a built-in filter, usually $15-30 — is a genuine convenience: one vessel, no double-straining, easier cleanup. It is not required. The jar-and-strainer method makes the identical drink for less money; it just takes one extra step.
Even against the cheapest store-bought option, homemade cold brew wins easily — and against a café cold brew, it isn’t close. Savings per drink: about $3.56 versus a bottle, about $4.52 versus café (comparing this guide’s 8oz homemade serving to a typical grocery bottle and café order — see our Cold Brew Concentrate recipe for the full per-serving math these figures are pulled from).
Assumptions: $16/lb beans, ~85g (1 cup) coarse grounds steeped in 32oz cold water for 1:4 concentrate, diluted roughly 1:1 for a ready-to-drink 8oz serving — the same figures published on our Cold Brew Concentrate recipe card, not a separate estimate. Grocery and café prices are current market averages and will vary by brand/city — the gap holds either way.
How Long to Steep (Counter vs. Fridge)
- 12-16 hours at room temperature: extraction moves a bit faster than in the fridge; convenient if you start before bed and want it ready by morning.
- 18-24 hours in the fridge: slower, more gradual extraction. Some people find it gives a slightly cleaner cup, since there’s less risk of accidentally over-steeping while you’re out of the house all day.
- Taste along the way the first few times you make it, note what hits your preference, then just set a timer for that number going forward — this is genuinely a “make it once, know your number” method.
- Steeping past 24 hours doesn’t ruin it instantly, but it trends more bitter and less balanced the longer it goes — same as any other over-extraction.
How Long It Keeps
- Concentrate: sealed and refrigerated, about 1-2 weeks without a meaningful drop in quality.
- Diluted to ready-to-drink strength: best within 3-4 days — it’s already been watered down, so it oxidizes and flattens faster than concentrate does.
- Keep concentrate in a sealed jar rather than left open in the fridge — coffee is genuinely good at picking up other food smells.
What to Do With Your Concentrate
Once you’ve got concentrate in the fridge, it’s the base for most of the iced drinks on this site. Pour it over ice with milk for a simple iced latte-style drink, or use it as the coffee base in our Proffee (Protein Cold Brew) recipe — that recipe assumes you already have concentrate on hand and picks up exactly where this guide leaves off. See How Much You’ll Save Making Coffee at Home for how a habit like this adds up over a year.
Common Mistakes
- Grinding too fine. Turns the steep muddy, makes straining harder, and pulls out more bitterness than you want.
- Using hot or warm water “to speed it up.” That’s not cold brew anymore — that’s brewing hot coffee and cooling it, which is iced coffee, and it tastes more acidic for a real chemical reason, not just a texture difference.
- Skipping the second strain. A mesh strainer alone leaves fine sediment behind that makes the finished drink gritty.
- Drinking concentrate at full strength and judging it that way. It’s brewed intentionally strong — dilute it before deciding whether you like the flavor.
- Leaving grounds in past 24 hours because you forgot about it. Set a timer; the flavor genuinely drifts toward bitter and muddy the longer it over-steeps.
Troubleshooting
- Tastes weak or watery, even as concentrate → steep longer next time, or use a stronger ratio (more grounds per cup of water).
- Tastes bitter or harsh → cut the steep time back, grind slightly coarser, or dilute more before drinking — concentrate that’s fine on its own can still taste bitter if you drink it too strong.
- Gritty or sludgy at the bottom of the glass → strain again through a finer filter (cheesecloth or a coffee filter) before storing.
- Tastes sour or flat → usually stale beans, not a steeping problem — cold brew is forgiving on technique but still needs reasonably fresh coffee to taste good.
- Cloudy or off-smelling after a week or more → same rule as any food in your fridge: if it smells off, it’s past its window. Toss it and start a fresh batch.
Recipe Card Summary
Basic Cold Brew Concentrate
- 1 cup (about 85g) coarse-ground coffee : 4 cups (32oz) cold water
- Steep: 12-16 hours room temp, or 18-24 hours fridge
- Strain twice: mesh strainer, then cheesecloth/coffee filter/nut-milk bag
- Dilute roughly 1:1 with water, milk, or ice to drink
- Keeps: ~1-2 weeks refrigerated as concentrate, 3-4 days once diluted
- Cost: ~$0.43/8oz serving vs. ~$3.99 bottled or ~$4.95 at a café (16oz)
FAQ
Is cold brew the same as iced coffee?
No. Iced coffee is hot-brewed coffee that’s chilled or poured over ice — it went through heat first. Cold brew never touches heat; it’s steeped in cold or room-temperature water for 12-24 hours. That difference in process is why cold brew tastes smoother and less acidic even from identical beans.
Do I need a special cold-brew maker?
No. A jar or pitcher plus a strainer and a piece of cheesecloth (or a coffee filter) makes the same drink as a dedicated cold-brew maker. The dedicated version is just more convenient to strain and clean, not a different result.
How long does cold brew concentrate last?
About 1-2 weeks refrigerated as concentrate. Once you dilute it to drinking strength, use it within 3-4 days for the best flavor.
Is cold brew stronger than regular coffee?
The concentrate is much stronger by design — that’s the point, since it’s meant to be diluted. Diluted to a normal ready-to-drink ratio (about 1:8), it’s comparable in strength to a regular cup, though many people find it has more caffeine per ounce than drip because of how much coffee goes into the steep.
Can I use hot water to make it faster?
That’s iced coffee, not cold brew — using heat changes what gets extracted and gives you a more acidic result. If you’re in a hurry, iced coffee is a fine drink on its own, but it isn’t a substitute technique for cold brew.