The best ratio of coffee grounds to water for making cold brew coffee is 1:4 or 1:5. This means using 1 part coffee grounds to 4 or 5 parts water. However, adjust the exact ratio according to your taste preferences. Strong Cold Brew: 1:4 ratio (1 part coffee grounds to 4 parts water) - This results in a strong, more concentrated cold brew. Balanced Cold Brew: 1:5 ratio (1 part coffee grounds to 5 parts water) - This is a more common ratio, providing a balanced and flavorful cold brew without being overly strong or weak. Light Cold Brew: 1:6 ratio (1 part coffee grounds to 6 parts water) - If you prefer a milder and less intense cold brew, this ratio will produce a lighter flavor.