How to Make Cold Brew Coffee at Home

The short answer

Cold brew is coarse-ground coffee steeped in room-temperature or cold water for 12-24 hours, then filtered — no heat involved at any point. Use a 1:8 ratio for a concentrate you'll dilute later, or 1:15 if you want to drink it straight from the fridge. Steep 16 hours as a solid default and adjust from there based on taste.

This is not iced coffee. Iced coffee is hot-brewed coffee poured over ice — same extraction chemistry as your morning pour-over, just chilled fast. Cold brew is a completely different extraction, done cold from the start, and it tastes different because of it — smoother, less acidic, less bitter.

Ratio and grind

For a concentrate — the kind you cut with water or milk before drinking — use 1:8, meaning 100g of coffee to 800g (roughly 800ml) of water. That gives you a strong base you dilute 1:1 with water or milk when serving. If you'd rather make something ready to drink straight over ice with no dilution step, go 1:15.

Grind coarse — coarser than French press, more like cracked pepper or coarse gravel. A fine grind here doesn't speed anything up (there's no heat pushing extraction faster) — it just makes for a much harder, muddier filtering job later and can turn the batch bitter and over-extracted from the extra surface area sitting in contact with water for so long.

Steep time

Somewhere between 12 and 24 hours works, at room temperature or in the fridge. Room temp extracts a bit faster — 12-16 hours is usually enough. In the fridge, extraction slows down, so you'll want closer to 18-24 hours. There's no meaningful flavor benefit to going past 24 hours; you're just risking a flatter, over-extracted result.

Taste-test at the 12-hour mark if you're dialing this in for the first time, then again every few hours until it tastes right to you — that's the only reliable way to find your own preferred steep time, since bean freshness and grind consistency both shift it.

Filtering — the part people skimp on

A single pass through a mesh bag or basket filter usually isn't enough — you'll get grit in the final pour. Do it in two stages: first strain out the bulk of the grounds through a fine mesh bag or a strainer lined with cheesecloth, then run that liquid through a paper coffee filter (a pour-over cone works fine, no coffee needed, just the filter) to catch the fine sediment. It's slow — the fine grounds clog paper filters — so do it in batches or let gravity work over 20-30 minutes.

How it differs from iced coffee, really

Iced coffee starts hot — you brew it like normal drip or pour-over, then either chill it or pour it directly over ice. Because heat drives extraction faster and pulls out different compounds (more acids, more aromatics), iced coffee tastes closer to hot coffee, just cold — brighter, sometimes a little more acidic once diluted by melting ice.

Cold brew never sees heat. The long, cold steep pulls out sugars and body but leaves a lot of the acid-forward and bitter compounds behind, which is why it drinks smoother and less sharp. Neither is "better" — they're genuinely different drinks that happen to both be served cold.

Practical steps

1. Coarse grind, 1:8 (concentrate) or 1:15 (ready-to-drink) ratio.
2. Combine coffee and room-temp or cold water in a jar or pitcher.
3. Steep 12-24 hours (16 is a good default), fridge or counter.
4. Strain through mesh, then filter again through paper.
5. Dilute concentrate 1:1 with water or milk before drinking; serve ready-to-drink batches straight over ice.