Cold Brew Coffee Ratio

"What's the cold brew ratio" has two right answers, because cold brew comes in two forms that get brewed at genuinely different strengths. A concentrate, meant to be cut with water, milk or ice before drinking, steeps at roughly 1:5 — a 100g dose in about 500ml of water. Something closer to ready-to-drink, meant to be poured over ice and consumed without further dilution, steeps lighter, toward 1:12, the same 100g dose spread across 1.2 liters instead.

Why the same drink has two starting points

A 12-24 hour steep at room temperature or in the fridge extracts slowly and gently compared to hot brewing, which is why cold brew tolerates such a wide ratio range without turning bitter the way an over-strong hot brew would. That slack is exactly what lets two very different serving styles share one method: brew concentrated and dilute to taste at serving time, or brew once at drinking strength and skip the dilution step. Neither is more "correct" — they're different finished products from the same steep.

The concentrate math

At 1:5, a 100g dose yields about 500ml of concentrate, strong enough that most people cut it roughly 1:1 with water, milk, or a milk alternative before drinking — which puts the effective strength in the cup closer to 1:10 once diluted, even though the brew itself was 1:5. This is the version that keeps in the fridge longest (a week or more, sealed) and lets you make one batch and adjust the final strength cup by cup depending on mood or what you're mixing it with.

The lighter, drink-it-straight version

Some recipes lean lighter than even this page's 1:12 light preset — closer to 1:15 — specifically so the result can go straight over ice with no dilution step at all. If you've made cold brew at 1:8 or 1:5 and found it needs cutting before it's drinkable, that's not a mistake; it's a concentrate, and diluting it is the intended next step, not a sign you brewed it wrong.

Working out a batch

Divide your target water volume by 5 for a true concentrate, by 8 for a middle-strength brew meant for light dilution, or by 12 for something close to drinkable as-is. A 1-liter batch at 1:8, for example, calls for 125g of coarsely ground coffee. The ratio calculator runs this for any batch size and any of the three presets directly.

Coarse grind, long steep, and what goes wrong

Cold brew wants a notably coarse grind — coarser than French press — because 12+ hours of contact time will over-extract a finer grind into bitterness regardless of ratio. If a batch comes out watery and flat rather than smooth, the fix is almost never more steep time; it's raising the ratio toward the concentrate end or checking the grind isn't too fine and choking the steep. The watery cold brew page covers this distinction directly.

Milk, ice and the ratio you actually taste

Whichever ratio you brew at, adding ice or milk at serving time dilutes the cup further than the brew ratio alone suggests — a concentrate poured over a full glass of ice can end up closer to 1:14 or 1:16 by the time it's melted partway, even though it left the fridge at 1:5. That's worth accounting for deliberately rather than discovering it halfway through the glass: brew stronger than you think you want if ice or milk is going in immediately after pouring.

For steep time, filtration method (cloth, paper, or a dedicated cold brew maker), and how temperature during the steep changes the final flavor, see the full cold brew guide.