🧊 Cold Brew Concentrate Calculator

Enter your desired batch size and steeping ratio to calculate coffee grounds needed, then see the dilution ratio for serving.

Concentrate Batch Size (fl oz)

Steeping Ratio (1 : X)

Serving Dilution (concentrate : water)

Two ratios, not one

Cold brew has a steeping ratio and a serving dilution, and the calculator keeps them separate:

water (ml) = batch (fl oz) × 29.5735
grounds (g) = water (ml) / steeping ratio
serve as 1 part concentrate : D parts water

A 32 fl oz batch is 946 ml of cold water. At 1:4 that takes 237 g of coarse grounds. Steeping accepts 1:2 to 1:8 and dilution 0.5 to 3. The number that actually reaches your glass is the two multiplied together: 1:4 concentrate cut 1:1 drinks like a 1:8 brew, and cut 1:2 it drinks like 1:12.

Time does the work that heat normally would

Grind coarse. Cold water extracts slowly, so fines sit in the batch for a full day pulling out bitterness and then clog whatever you strain through.
12 to 24 hours. Twelve at room temperature, closer to 24 in the fridge. Past a day the gains stop and woody flavours start.
Strain twice. A mesh sieve first, then a paper filter or cloth, or the concentrate keeps brewing on suspended fines in the jug.

Wet grounds hold about twice their weight in water. At 1:4 those 237 g soak up around 470 ml of your 946 ml, so you strain out roughly half a batch. Either add the retained amount to the steeping water or expect the yield to be well under the size you entered.

Frequently asked questions

What is the best ratio for cold brew concentrate?

1:4 to 1:5 by weight for something you dilute, and 1:8 if you want to drink it straight. At 1:4 a 946 ml batch needs about 237 g of grounds.

How do I dilute cold brew concentrate?

Start at one part concentrate to one part water or milk, then adjust. Ice counts - a full glass of it can add another half part as it melts.

How long does cold brew concentrate keep?

Seven to ten days sealed in the fridge, and it is noticeably flatter after about a week. Diluted cold brew keeps far less well, so cut it by the glass rather than the jug.