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Cold Brew Ratio Guide: 1:4 to 1:16, Explained
Every cold brew argument eventually becomes a ratio argument. Here's the whole map.
A cold brew ratio is the weight of coffee against the weight of water: 1:5 means 1 gram of coffee for every 5 grams of water. It is the single biggest lever you control — bigger than beans, bigger than steep time — and it's also where most recipes go wrong, because they talk in cups and scoops.
Why weight, not volume
A "cup of ground coffee" can weigh anywhere from about 65 to 95 grams depending on roast and grind. Darker roasts are less dense; finer grinds pack tighter. Two people following the same volume recipe can end up with brews 30 percent apart in strength and both wondering what they did wrong. Nothing — the recipe lied to them. Water at least behaves: 1 ml weighs 1 g, so 1,000 ml is 1,000 g, every time.
A scale removes the entire category of error. This is the hill the Snob dies on, and it's why our methodology records everything in grams.
The ratio map
| Ratio | Strength | What it is | Use it for |
|---|---|---|---|
| 1:4 | Very strong concentrate | Syrupy, intense, needs cutting | Milk drinks, big-batch entertaining |
| 1:5 | Strong concentrate | The Snob house ratio | Everything — dilute to taste |
| 1:8 | Ready to drink | Café-strength over ice | Drinking black, straight from the fridge |
| 1:10 | Ready to drink, lighter | Smooth, easy, session coffee | All-day sipping |
| 1:12 | Light | Tea-like body | Delicate single origins |
| 1:16 | Very light | Basically cold filter coffee | Experiments; most beans get watery here |
Concentrate vs ready-to-drink
Brew concentrate. This is the rare opinion we hold without hedging.
A 1:4 or 1:5 concentrate cut 1:1 with water lands at an effective 1:8–1:10 in the glass — the same place a ready-to-drink brew ends up, except the concentrate also does milk drinks, iced lattes, cocktails, and hot americano-style coffee without tasting thin. Ready-to-drink brews do exactly one thing. Concentrate is one batch pretending to be five products.
The dilution math is simpler than it sounds: equal parts concentrate and water halves the strength, so 1:5 becomes 1:10 in the glass. If you like it bolder, cut with less water; the concentrate doesn't care.
The yield tax
Coffee grounds hold on to roughly twice their weight in water. Brew 200 g of coffee with 1,000 g of water and you pour off about 600 ml, not 1,000. Every "why did I get so little?" complaint in every cold brew forum is this, unaccounted for.
The fix is to plan backward from the amount you want to drink. Or let the ratio calculator do it — it adds the absorbed water back in automatically, which is the entire reason we built it.
Where to start
If you're new: 1:5, 16 hours, cut 1:1. The full step-by-step lives in How to Make Cold Brew. Adjust one variable at a time from there — ratio first, then steep time, then grind. Change all three at once and you'll learn nothing except that something is different.