The no-nonsense guide to cold brew coffee: exact ratios, steep times, caffeine numbers and the beans that actually taste good over ice.
Four steps, one jar, zero equipment you don't already own. This makes roughly one litre of concentrate — about eight drinks once diluted.
1100 g of medium-roast beans on a coarse setting. Even, chunky grounds keep the long steep clean instead of muddy.
2Add 500 g of filtered water for concentrate. Stir until every ground is wet — dry pockets mean weak, uneven extraction.
3Cover and leave it on the counter, or push to 24 hours in the fridge for a rounder, less bitter cup.
4Strain through a fine mesh, then a paper filter for a silkier body. Store sealed and it keeps for up to two weeks.
Ratios are coffee to water by weight. Start here, then adjust by 10% in either direction to taste.
| Style | Ratio | Steep | Serve |
|---|---|---|---|
| Cold brew concentrate | 1:5 | 16-18 hrs | Dilute 1:1 before drinking |
| Ready-to-drink cold brew | 1:8 | 18-20 hrs | Pour straight over ice |
| Cold brew latte base | 1:4 | 20-24 hrs | Cut with milk or oat milk |
| Japanese iced (flash) coffee | 1:15 | 3-4 min | Brew hot onto ice |
Iced coffee is hot-brewed then chilled: bright, acidic, best drunk the same day. Cold brew never touches heat: rounder, sweeter, heavier bodied, and it keeps for two weeks. If your stomach dislikes coffee acidity, cold brew is the swap.
A 1:5 concentrate runs roughly 400-500 mg of caffeine per 8 oz. Diluted 1:1 you are near 200-240 mg — about two cups of drip. Nitro cold brew sits in the same range; the nitrogen only changes texture, not strength.
Cold brew is coffee steeped in cool or room-temperature water for 12 to 24 hours instead of being brewed with heat. The slow, low-temperature extraction pulls out sugars and caffeine while leaving behind many of the bitter acids that hot brewing releases, which is why cold brew tastes smooth, sweet and chocolatey.
Cold brew concentrate is much stronger by volume, typically 2 to 3 times the caffeine of drip coffee before dilution. Most people cut it 1:1 with water or milk, which lands a finished cup around 150-240 mg of caffeine versus roughly 95-165 mg for drip.
Use 1:5 by weight (200 g coffee to 1000 g water) for a concentrate you will dilute, or 1:8 for a ready-to-drink batch. Weigh your coffee if you can; volume scoops vary wildly with grind size.
16 to 18 hours at room temperature or 20 to 24 hours in the fridge is the sweet spot. Under 12 hours tastes thin and sour; past 24 hours the brew turns woody and astringent.
Iced coffee is brewed hot and then chilled or poured over ice, so it keeps the bright acidity of hot coffee. Cold brew never meets heat, so it is lower in perceived acidity, heavier in body, and stays fresh in the fridge for up to two weeks.
Grind coarse, like raw sugar or French press grind, so the long steep does not over-extract. Medium and medium-dark roasts from Brazil, Colombia, Guatemala or Sumatra give the cocoa, caramel and nut notes most people want in cold brew.