Cold Brew Ratio Calculator
Calculate cold brew ratio for your recipes with our free tool. Get precise conversions, nutritional info, and serving adjustments.
Calculator
Adjust values & calculateOptimal range — balanced and smooth
Formula
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.
Last reviewed: December 2025
Worked Examples
Example 1: Classic Concentrate Batch
Example 2: Ready-to-Drink Large Batch
Background & Theory
The Cold Brew Ratio Calculator applies the following established principles and formulas. Cooking and food preparation involve a surprisingly rich set of mathematical relationships that govern texture, flavour, nutrition, and safety. Recipe scaling is perhaps the most immediately practical: to adjust a recipe serving 4 to serve 10, every ingredient quantity is multiplied by the ratio 10/4 = 2.5. This works straightforwardly for most ingredients, but leavening agents, salt, and strong spices often need more conservative scaling because their effects are not strictly linear at larger volumes. Baker's percentage is a professional notation system in which every ingredient is expressed as a percentage of total flour weight. If a dough uses 1000 g flour and 650 g water, the hydration is 65%. This system makes formulas portable across batch sizes and allows bakers to adjust hydration, enrichment, or fermentation characteristics with precision. Temperature conversion between Fahrenheit and Celsius (°C = (°F − 32) × 5/9) is essential when following recipes written for a different regional audience. The Maillard reaction, responsible for browning and the development of complex flavour compounds in bread crusts, roasted meats, and caramelised vegetables, occurs most rapidly above approximately 140°C (285°F) and accelerates with temperature. Yeast activity is highly temperature-sensitive: active dry yeast proofs optimally between 38°C and 43°C (100°F–110°F), and temperatures above 60°C are lethal to yeast cells. Volume-to-weight conversions in cooking rely on ingredient density, which varies significantly: a cup of all-purpose flour weighs approximately 120–130 g, while a cup of honey weighs around 340 g. Relying on volume for dense or variable-density ingredients introduces meaningful measurement error. The pH of a batter determines how leavening agents behave: baking soda (sodium bicarbonate) requires an acid such as buttermilk or vinegar to activate, while baking powder contains its own acidic component and works in neutral batters. Nutritional density calculations, expressed as kilocalories per 100 g, allow comparison of foods on a consistent basis, supporting dietary planning and labelling compliance.
History
The history behind the Cold Brew Ratio Calculator traces back through the following developments. The culinary arts have ancient roots spanning every human civilisation, but the formalisation of cooking as a measurable, teachable discipline emerged gradually over centuries. Ancient Egyptian, Greek, and Roman texts contain references to food preparation, and medieval European monasteries developed sophisticated brewing and baking traditions that implicitly encoded ratios and techniques passed through apprenticeship. The most transformative figure in modern professional cooking was Auguste Escoffier, whose systematisation of classical French cuisine in the late 19th and early 20th centuries created a codified brigade system and a catalogue of standardised preparations that became the foundation of professional culinary training worldwide. His work, particularly Le Guide Culinaire published in 1903, treated cooking as a discipline with repeatable, transmissible formulas rather than purely intuitive craft. Home economics emerged as a formal academic discipline in the 19th century, partly in response to industrialisation and urbanisation. Figures such as Catharine Beecher and later Ellen Richards in the United States worked to apply scientific principles to domestic cooking and nutrition, eventually institutionalising the subject in schools and universities. Standardised recipe development became central to the food industry in the 20th century as mass food manufacturing required consistent, scalable formulas. The USDA introduced its first food pyramid in 1992 as a public health tool to communicate recommended nutritional ratios to a general audience, though the model has been revised multiple times since. MyPlate replaced the pyramid in 2011 with a simpler visual. Molecular gastronomy, pioneered in the 1990s by chefs such as Ferran Adria at elBulli and Heston Blumenthal at The Fat Duck, brought laboratory techniques and rigorous scientific analysis to high-end cooking, exploring the chemistry of gels, foams, emulsifications, and temperature-controlled preparations. Food calorie labelling laws, mandated on packaged foods in the United States since 1990 under the Nutrition Labeling and Education Act, formalised the expectation that consumers would engage with nutritional arithmetic as part of daily food choices.
Frequently Asked Questions
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.
Why might my result differ from another tool or reference?
Differences typically arise from rounding conventions, the specific version of a formula (for example, simple vs compound interest), or unit inconsistencies between inputs. Check that both tools are using the same formula variant and the same units. The References section links to the authoritative source behind the formula used here.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy