Cold Brew Ratio Calculator
Calculate cold brew ratio for your recipes with our free tool. Get precise conversions, nutritional info, and serving adjustments.
Formula
Yield = Water (ml) - Coffee (g) x 2; Ratio = Water / Coffee
Coffee grounds absorb approximately twice their weight in water. The ratio of water to coffee determines brew strength: 1:4-6 for concentrate, 1:8 for strong, 1:12-16 for ready-to-drink. Caffeine is estimated at ~6mg per gram of ground coffee.
Worked Examples
Example 1: Classic Concentrate Batch
Problem: You want to make cold brew concentrate using 100g of coarsely ground coffee with 500ml of water, steeped for 18 hours in the fridge. How much concentrate will you yield and how many servings?
Solution: Ratio: 1:5 (coffee to water) — ideal for concentrate\nWater absorbed by grounds: 100g x 2 = 200ml\nYield: 500ml - 200ml = 300ml concentrate\nDiluted 1:1 for serving: 300ml x 2 = 600ml total\nAt 150ml per serving: 600ml / 150ml = 4 servings\nCaffeine per serving: ~150mg
Result: Yield: 300ml concentrate | 4 servings diluted | ~150mg caffeine each | Cost: ~$1.47/serving
Example 2: Ready-to-Drink Large Batch
Problem: Make ready-to-drink cold brew for a party with 60g of coffee and 720ml of water (1:12 ratio). Steep 16 hours at room temperature.
Solution: Ratio: 1:12 (ready-to-drink strength, no dilution needed)\nWater absorbed: 60g x 2 = 120ml\nYield: 720ml - 120ml = 600ml\nPer serving (200ml glass): 3 servings\nCaffeine per serving: ~120mg\nSteep time at room temp: 16 hours is optimal
Result: Yield: 600ml ready-to-drink | 3 servings | ~120mg caffeine each | Cost: ~$1.18/serving
Frequently Asked Questions
What is the best coffee-to-water ratio for cold brew?
The ideal coffee-to-water ratio depends on whether you are making a concentrate or a ready-to-drink brew. For cold brew concentrate, which is meant to be diluted before serving, a ratio of 1:4 to 1:6 by weight is recommended, meaning one gram of coffee for every four to six grams of water. For ready-to-drink cold brew that requires no dilution, use a ratio of 1:12 to 1:16 similar to traditional hot brewing ratios. Most specialty coffee professionals recommend starting with a 1:5 ratio for concentrate and diluting with equal parts water or milk when serving. The coarseness of your grind also matters significantly, as finer grinds extract more quickly and can lead to over-extraction during the long steeping period typical of cold brew preparation.
How long should I steep cold brew coffee?
Cold brew coffee should steep for 12 to 24 hours, with 16 to 20 hours being the sweet spot for most recipes and coffee varieties. Steeping for less than 12 hours typically results in under-extraction, producing a thin, sour, and acidic brew that lacks the characteristic smooth sweetness of properly made cold brew. Steeping for more than 24 hours risks over-extraction, which introduces harsh, bitter, and astringent flavors similar to burnt or woody notes. The steeping temperature also affects timing: room temperature extraction occurs faster than refrigerator cold extraction. If steeping at room temperature around 20 degrees Celsius, aim for 12 to 16 hours. If steeping in the refrigerator at approximately 4 degrees Celsius, extend the time to 18 to 24 hours for optimal flavor development.
What grind size should I use for cold brew?
Cold brew requires a coarse grind, similar to the texture of raw sugar or coarse sea salt. This is coarser than what you would use for a French press. The reason for this coarse grind is the extremely long contact time between the coffee and water. A finer grind would lead to over-extraction during the 12 to 24 hour steeping period, resulting in bitter and unpleasant flavors. Coarse grounds also make filtration much easier, as fine particles can clog filters and create a muddy, silty final product. If you do not have a grinder capable of producing a consistent coarse grind, many coffee shops will grind beans to cold brew specifications upon request. Using pre-ground coffee designed for drip brewers is not recommended as the particle size is too fine for proper cold brew extraction.
How much caffeine is in cold brew compared to regular coffee?
Cold brew concentrate typically contains significantly more caffeine per fluid ounce than regular drip coffee because of the higher coffee-to-water ratio used in its preparation. A typical cold brew concentrate made at a 1:5 ratio contains approximately 200 to 300 milligrams of caffeine per eight ounces. However, since concentrate is usually diluted 1:1 or more with water, milk, or ice before drinking, the caffeine content in a finished serving is roughly comparable to or slightly higher than regular drip coffee at about 150 to 250 milligrams per serving. The extended steeping time actually extracts caffeine very efficiently despite the cold water temperature. Factors affecting caffeine content include the coffee bean variety with Robusta containing nearly twice the caffeine of Arabica, the grind size, the ratio, and the steeping duration.
How long does cold brew coffee last in the refrigerator?
Properly made cold brew concentrate stored in a sealed container in the refrigerator will maintain optimal flavor for approximately 7 to 10 days, though it remains safe to drink for up to two weeks. The concentrate format lasts longer than diluted cold brew because the higher concentration of dissolved coffee compounds acts as a mild preservative. Once diluted, cold brew should be consumed within 2 to 3 days for best flavor quality. Signs that cold brew has gone past its prime include a noticeably more bitter or woody taste, loss of the characteristic smooth sweetness, and eventually visible mold growth. To maximize shelf life, store in glass containers with tight-fitting lids, minimize exposure to air, and always use clean utensils. Never leave cold brew at room temperature for extended periods after the initial steeping process is complete.
What formula does Cold Brew Ratio Calculator use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.