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Cold Brew

Cold Brew Ratio: How Much Coffee Per Litre of Water

August 27, 2026

Cold brew needs a lot more coffee than hot brewing, and the ratio you choose decides what ends up in your fridge. It is one of the key numbers in our cold brew guide, and the one most worth getting right.

Why so much coffee

Cold water extracts slowly and less completely than hot water, even over many hours. To end up with a drink that has real flavour and body, you need to start with more grounds per gram of water than you would for pour-over.

Common ratios

Ratios here are coffee to water, by weight:

  • 1:4 to 1:5 makes a strong concentrate. Dilute with water or milk before drinking, usually 1:1.
  • 1:8 is a medium strength. Some people drink it straight over ice, others add a splash of milk.
  • 1:10 to 1:12 is roughly ready to drink straight from the jar.

If you are not sure, start at 1:8. It is easy to dilute later, and hard to fix a weak batch.

Weigh, do not scoop

Cold brew batches are big, and small errors add up. A coffee scale that handles a couple of kilograms lets you weigh both coffee and water directly into your jar. For 1:8, that might be 125 grams of coffee and 1,000 grams of water.

Ratio and steep time go together

A stronger ratio does not need as long a steep to taste full, and a weaker ratio can take a little longer. If you change one, check the other. Our article on cold brew steep time explains the trade-off in more detail.

Concentrate or not

The big question with ratio is whether you want to brew a concentrate. Concentrate takes up less fridge space and is flexible, since you can make a strong or mild drink from the same jar. Ready-to-drink is simpler and more consistent. We weigh up both options in cold brew concentrate vs ready-to-drink.

Adjusting to taste

  • Too weak or watery: use more coffee next batch, or extend the steep slightly.
  • Too strong or heavy: dilute more when serving, or use less coffee next time.
  • Bitter or woody: that is more often a steep time problem than a ratio problem.

Change one thing per batch and keep a note.

A simple recipe at 1:8

  1. 125 grams of coarse coffee.
  2. 1,000 grams of cold filtered water.
  3. Steep 16 to 18 hours in the fridge.
  4. Strain and serve over ice, adding water or milk to taste.

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