How to Make Cold Brew Coffee at Home: Ratio, Steep Time & Best Beans
Quick answer
Cold brew is coffee steeped in cold or room-temperature water for 12–18 hours: 100 g of extra-coarse grounds to 500 g of water, a 1:5 ratio, makes a concentrate you cut roughly 1:1 before drinking. No heat, no boiling, no bitterness — just smooth, sweet coffee that keeps for days.
Why cold brew tastes so smooth
Hot water extracts everything from coffee fast — the good, the bitter, and the sharp. Cold water works slower and more selectively, pulling out sweetness and chocolatey body while leaving many of the harsher acids and bitter compounds behind. The result is a mellow, dangerously drinkable cup, typically noticeably less acidic than hot-brewed coffee.
The recipe
- Grind coarse. Think breadcrumbs, not powder. Too fine and you'll get sludge and over-extraction.
- Combine at 1:5. 100 g of coffee to 500 g (ml) of water makes a concentrate. No scale? Use about 1 cup of ground coffee per 2 cups of water.
- Steep 12–18 hours. Room temperature or fridge, covered. Longer means stronger — past ~20 hours it can turn woody.
- Strain. Through a fine mesh, paper filter, or a proper cold brew maker.
- Dilute and serve. Cut the concentrate roughly 1:1 with water or milk over ice, then adjust to taste.
Cold Brew Ratio Chart by Batch Size (1 Quart, Half Gallon, 1 Gallon)
The recipe above fills a jar. Most people make cold brew because they want a fridge full of it, so here is the same 1:5 concentrate scaled up. The cup measures assume roughly 100 g of grounds per cup — use a scale if you own one, because the scoop-and-hope method drifts badly at these volumes.
| Batch | Coffee (grams) | Coffee (cups, approx.) | Water | Steep | Finished coffee after 1:1 dilution |
|---|---|---|---|---|---|
| 1 quart | 190 g | 2 cups | 950 g (32 oz) | 12–18 hrs | About 1.5 quarts |
| Half gallon | 380 g | 4 cups | 1.9 L (64 oz) | 12–18 hrs | About 3 quarts |
| 1 gallon | 760 g | 8 cups | 3.8 L (128 oz) | 14–18 hrs | About 1.5 gallons |
Finished volumes are approximate, because the grounds keep some of the water — count on losing roughly a cup per quart brewed. Two practical notes. A gallon of concentrate is close to two pounds of coffee, so decide whether you actually want concentrate: if you'd rather brew ready-to-drink and skip the dilution step, use a much weaker 1:8 to 1:10 ratio and pour it straight over ice. And extra-coarse grind matters more as the batch grows, because more coffee means more fines, and fines are what turn a gallon of cold brew into silt.
If ratios in general are your sticking point, the coffee-to-water ratio guide lays out every method side by side. And if you want the concentrate to hit harder, tighten toward 1:4 rather than steeping it into next week — the same logic that applies to brewing strong coffee with any method: more coffee, not more time.
Cold brew vs. iced coffee
They're not the same drink. Iced coffee is hot-brewed coffee poured over ice — brighter, more acidic, ready in minutes. Cold brew never touches heat, trades brightness for smoothness, and takes hours. Neither is wrong; one is just more patient than the other.
Nitro Cold Brew and Japanese Iced Coffee: Two Variations Worth Trying
Nitro cold brew is cold brew with nitrogen infusion — nitrogen forced into the coffee and served on tap through a restrictor plate. The tiny bubbles give it a cascading pour, a thick head, and a texture people read as creamy and sweet even though there's no dairy and no sugar in it. You can get close at home with a nitro tap kit or a whipped-cream charger. You cannot get close by shaking the jar.
Japanese iced coffee — flash brew — goes the other direction entirely. You brew hot coffee directly onto ice, usually as a pour over with roughly half the brew water replaced by ice sitting in the carafe. The coffee chills the instant it's brewed, which locks in the volatile aromatics that cold brew never extracts in the first place. Cold brew is smooth and low-acid; flash brew is bright, floral and unmistakably fresh. If cold brew has always tasted a bit flat to you, this is probably the drink you actually wanted. Our pour over guide covers the technique — brew at your usual ratio and count the ice as part of the water.
One upgrade improves either drink: a paper-filter polish. After straining the concentrate through mesh, run it once more through a paper filter. It catches the last of the fines and drops the TDS slightly, trading a little body for a much cleaner finish.
Is Cold Brew Really Less Acidic? What the pH Says
We said "low acid" up top, which deserves a number. Hot-brewed coffee typically measures somewhere around pH 5. Cold brew usually measures higher — commonly reported around pH 6, closer to neutral. Treat both figures as approximate: they shift with bean, roast level, grind, ratio and steep time, and published measurements don't fully agree on how large the gap is.
What's less disputed is the direction and the reason. Cold water is a poor solvent for several of the sharper acids that hot water strips out in minutes, so cold brew simply extracts fewer of them. Perceived acidity and measured pH aren't the same thing either — cold brew's low bitterness and rounder sweetness make it taste smoother than the numbers alone suggest. If hot coffee bothers your stomach, cold brew is worth trying, but that's a personal experiment rather than a medical claim.
How Much Caffeine Is in Cold Brew?
More than most people expect, and the reason is arithmetic rather than magic: a big dose of coffee plus a long steep makes a loaded concentrate. How much of it lands in your glass depends entirely on how far you dilute — the same batch can be a mild iced coffee or a genuinely bad decision, depending on the pour. Undiluted concentrate is not a serving size.
For actual milligram figures by brew method and serving size, we keep them all in one place: how much caffeine is in a cup of coffee. Want the ritual without the jolt? Our decaf lives in Bone Yard, and it cold brews perfectly well.
The best beans for cold brew
Cold brewing mutes acidity and amplifies body, so chocolatey, nutty, low-acid roasts shine. From our lineup, Dead Man's Brew makes a rich, bittersweet concentrate, Coffin Break brings cocoa and toasted nuts, and Midnight Reaper leans smooth with maple sweetness. And yes — freshness still matters cold: stale beans make flat cold brew, which is why every bag is roasted after you order. Dark roasts live in Death Row, mediums in Crossroads.
FAQ
How long does cold brew keep?
Concentrate keeps up to two weeks refrigerated, but it's best inside the first week. Diluted cold brew is happiest within 2–3 days.
Is cold brew stronger than regular coffee?
Often, yes — per serving it usually carries more caffeine because of the high dose and long steep. Dilution decides the final strength.
Can I heat cold brew?
Absolutely. Warm the concentrate gently with hot water for a smooth, low-acid hot cup.
What grind size should I use for cold brew?
Extra-coarse — coarser than you'd use for French press. Over 12 to 18 hours even large particles extract plenty, while fines over-extract and leave sludge that no strainer fully removes.
Do I need a special cold brew maker?
No. A mason jar and a paper filter will do it, and a French press works as a cold brew vessel with the plunger doing the straining. Dedicated makers are convenience, not magic.
Why is my cold brew weak or watery?
Usually under-dosing or over-diluting. Check that you're actually at 1:5 by weight for concentrate, steep the full 12 to 18 hours, and cut it 1:1 rather than by eye. A weak batch is a ratio problem, not a steep-time problem. And no, cold brew concentrate isn't espresso — that's a pressure method, no matter what the drive-through menu calls it.
Grab a bag built for the long steep — shop fresh-roasted coffee, whole bean or ground. Every bag is $23.99, 100% specialty Arabica, roasted to order and shipped within two business days; orders of $40 or more ship free, backed by a 30-day money-back guarantee.