Cold Brew Coffee Ratio Guide

Cold brew is easy to make, but the ratio of coffee to water decides whether you end up with a smooth, rich drink or something weak and watery. Here’s how to choose a ratio and adjust it to your taste.

Concentrate vs Ready-to-Drink

There are two main approaches to cold brew.

Concentrate uses a lot of coffee and less water. You dilute it before drinking. It takes up less fridge space and gives you flexibility.

Ready-to-drink uses more water so you can pour it straight over ice. It’s simpler but takes up more room.

Common Ratios

All ratios here are by weight, coffee to water:

1:4 very strong concentrate, dilute 1:2 or more
1:5 strong concentrate, dilute about 1:1.5
1:8 mild concentrate, dilute about 1:1 or drink with lots of milk
1:10 to 1:12 ready to drink, especially over ice
1:15 light, similar to drip coffee strength

A good starting point for most people is 1:8. It’s strong enough to dilute but not so strong that small errors make it harsh.

Measuring by Weight

Weighing your coffee and water with a coffee scale is much more reliable than using cups. Coarse ground coffee is fluffy, and volume measurements can be off by 20 percent or more.

For a 1:8 batch:

100 g coffee
800 g water

That yields about 600 grams of concentrate, since the grounds absorb some water.

How to Dilute Concentrate

Start with equal parts concentrate and water or milk. Taste and adjust.

Too strong: add more water or milk
Too weak: add more concentrate next time
Tastes flat: try diluting with sparkling water for a brighter drink

Ice also dilutes as it melts, so make it slightly stronger if you serve it over a lot of ice.

Grind and Ratio Work Together

A coarse grind is essential for cold brew. Fine grounds extract too much over a long steep and can make the coffee bitter. They also clog filters.

If your cold brew tastes weak even at a strong ratio, the grind may be too coarse or the steep too short. If it tastes bitter, check your grind before changing the ratio. A grind size chart can help you find a starting point.

Steep Time and Ratio

Steep time also affects strength. A typical range is 12 to 24 hours.

Room temperature: 12 to 18 hours
In the fridge: 18 to 24 hours

Stronger ratios can usually handle shorter steeps. Weaker ratios need longer.

Adjusting for Beans

Roast level changes how strong the brew tastes.

Dark roasts produce bold, chocolatey cold brew and can handle weaker ratios. Light roasts often taste thin in cold brew, so a stronger ratio helps.

Comparing to Hot Methods

Cold brew ratios are much stronger than hot methods. A pour-over ratio usually sits around 1:16, and French press coffee around 1:12 to 1:15. That’s because cold water extracts less efficiently, so you need more coffee to get the same flavor.

A Simple Plan

If you’re new to making cold brew coffee at home:

Start with 1:8
Steep for 16 hours at room temperature
Filter and dilute 1:1
Adjust next time based on taste

Once you’ve made a few batches, you’ll know exactly how strong you like it.