How Much Coffee for Cold Brew? The Ratio Math by Batch Size

Cold brew hides two different drinks behind one name, and each one wants its own ratio. This is the math behind the site's cold brew ratio calculator tool. Concentrate steeps strong at 1:5 so it can survive dilution later. Ready-to-drink cold brew steeps at 1:8 instead and skips that dilution step entirely. Confuse the cold brew concentrate ratio with the ready-to-drink one and you'll end up with a jar that's either syrupy or embarrassingly thin.

The two ratios, and why they differ

At 1:5, 200 g of coarse coffee steeped in 1000 g (a liter) of cold water makes concentrate strong enough to take a real cut later. Strain it and you won't get a full liter back. Coarse grounds hold onto some of that water, so a 200 g batch usually yields somewhere around 800–900 ml of actual concentrate. Dilute that 1:1 with water or milk and you land close to 1.6–1.8 liters of finished coffee, roughly seven or eight 240 ml servings. Plan your jar and your fridge shelf around that final number, not the liter you started with.

Ready-to-drink skips dilution by brewing at drinking strength from the start. At 1:8, 125 g of coffee in 1000 g of cold water makes a jug you pour straight over ice, no second container, no math at serving time. It's the better choice when fridge space is tight, since a single jug replaces the concentrate-plus-water-jug combo. Concentrate is the better choice when you drink cold coffee daily and want a small container that stretches for two weeks instead of one that empties in three days.

Scales

0.1 g coffee scale with timer

Cold brew's batch sizes swing from 70 g up to 400 g of coffee depending on the jar, and a scoop can't track that range accurately. A 0.1 g scale catches the difference between 70 g and 75 g that a measuring cup never will, and its built-in timer doubles as a reminder for the 14–18 hour steep. It won't fit a two-liter batch's whole jug on the platform at once, so you're still taring in stages for the biggest jars.

Weighing your coffee and water is the cheapest fix for cups that taste different every day. The built-in timer handles pour-over pacing, and 0.1 g resolution is plenty for anything you'd brew at home.

Best for: Fixing inconsistent coffeeBest for: Learning ratiosBest for: Any brew method

Worth knowing: The membrane buttons can lag when they're wet

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This piece sticks to the ratio math. Grind size, steep time, and straining live in the site's cold brew guide, worth a look before your first batch. If your jar doesn't match any size above, the ratio calculator tool runs the same 1:5 or 1:8 division for whatever batch you're actually making, no mental math required at 11 pm the night before a party.