Cold Brew Concentrate Calculator
Calculate coffee grounds and water for cold brew concentrate at various strength ratios. Enter values for instant results with step-by-step formulas.
Formula
Coffee (g) = Total Brew Volume (mL) / Ratio Denominator
The ratio represents parts coffee to parts water by weight. For a 1:5 ratio, divide the total brew volume by 5 to get the coffee weight in grams. A yield factor of 0.85 accounts for water absorbed by the grounds during steeping.
Worked Examples
Example 1: Standard Batch for the Week
Problem: You want to make 8 servings of cold brew concentrate (8 oz each) at a 1:5 ratio with coarse grounds, steeping for 18 hours.
Solution: Total yield needed: 8 x 8 oz = 64 oz\nBrew volume (accounting for absorption): 64 / 0.85 = 75.3 oz\nCoffee grounds: 75.3 oz / 5 = ~426 grams (15 oz)\nWater: 75.3 oz - 15 oz = ~60 oz (7.5 cups)\nCaffeine per serving: ~318 mg (before dilution)\nEstimated cost: ~$9.75 total ($1.22 per serving)
Result: Use 426g (15 oz) coarse grounds with 60 oz water, steep 18 hours for 8 servings of concentrate
Example 2: Ready-to-Drink Light Cold Brew
Problem: Make 4 ready-to-drink servings at 1:12 ratio for a lighter, no-dilution-needed cold brew.
Solution: Total yield needed: 4 x 8 oz = 32 oz\nBrew volume: 32 / 0.85 = 37.6 oz (1,113 mL)\nCoffee grounds: 1,113 / 12 = ~93 grams (3.3 oz)\nWater: ~34.3 oz (4.3 cups)\nCaffeine per serving: ~139 mg\nEstimated cost: ~$2.15 total ($0.54 per serving)
Result: Use 93g (3.3 oz) coarse grounds with 34 oz water, steep 18 hours for 4 ready-to-drink servings
Frequently Asked Questions
What is the best coffee-to-water ratio for cold brew concentrate?
The standard ratio for cold brew concentrate is 1:5 (one part coffee grounds to five parts water by weight), which produces a strong, smooth concentrate meant to be diluted with equal parts water, milk, or ice before drinking. For extra-strong concentrate, use 1:4, which creates a very potent base ideal for coffee cocktails or adding to recipes. For ready-to-drink cold brew that needs no dilution, use 1:8 to 1:12 ratios. The 1:8 ratio produces a full-flavored cold brew similar to what you find at coffee shops. Lighter drinkers may prefer 1:15 for a mild, refreshing cold coffee that works well over ice.
How long should cold brew steep for best results?
Cold brew should steep for 12 to 24 hours, with 16 to 18 hours being the sweet spot for most people. Shorter steeping times (under 12 hours) produce a weak, under-extracted brew that tastes thin and watery. Between 12 and 16 hours, the brew develops good body and sweetness. At 18 to 20 hours, you get maximum extraction of desirable flavor compounds with smooth, chocolatey notes. Beyond 24 hours, over-extraction begins pulling out bitter and astringent compounds that create harsh, unpleasant flavors. Temperature also matters: steeping at room temperature extracts faster than refrigerator steeping, so reduce time by 2 to 4 hours for room temperature brewing.
Why does grind size matter for cold brew?
Grind size is critical because it determines the surface area exposed to water, which directly affects extraction rate and flavor. Coarse grinds (similar to raw sugar) are recommended for cold brew because the long steep time compensates for the reduced surface area, producing a smooth, low-acid concentrate. Medium grinds extract faster and can work with shorter steep times (10 to 14 hours) but risk over-extraction with longer steeping. Fine grinds are not recommended as they over-extract quickly even at cold temperatures, produce bitter, gritty coffee, and clog filters during straining. Consistent grind size is also important to ensure even extraction across all particles.
How much caffeine is in cold brew coffee?
Cold brew concentrate typically contains 150 to 250 milligrams of caffeine per 8-ounce serving before dilution, which is higher than regular drip coffee at about 95 milligrams per cup. However, cold brew concentrate is meant to be diluted, so the actual caffeine per serving depends on your dilution ratio. At 1:1 dilution, an 8-ounce glass of diluted cold brew contains roughly 100 to 150 milligrams of caffeine. The high caffeine content in the concentrate comes from the large amount of coffee grounds used relative to the water. Caffeine extraction increases with steeping time, so longer steeps produce more caffeinated results. Bean type also matters, with Robusta beans containing roughly twice the caffeine of Arabica.
Can I use any type of coffee beans for cold brew?
You can use any coffee beans for cold brew, but medium to dark roasts generally produce the best results. Dark roasts complement the cold brew process because the slow, cold extraction emphasizes smooth, chocolatey, nutty notes while minimizing the bitterness that dark roasts sometimes show in hot brewing. Medium roasts offer a balanced profile with more nuanced flavors. Light roasts can work but may taste thin or sour in cold brew because the acids that create brightness in hot coffee taste unpleasant when cold-extracted. Single-origin beans can produce interesting cold brews with unique flavor profiles. Freshly roasted beans (used 1 to 3 weeks after roasting) give the best flavor.
How long does cold brew last in the refrigerator?
Undiluted cold brew concentrate lasts 10 to 14 days in the refrigerator when stored in a clean, airtight container. The concentrate acts as a preserved form because of its high coffee solute concentration. Diluted cold brew (mixed with water or milk) should be consumed within 3 to 5 days as dilution reduces the preservative effect of concentration. After about 2 weeks, even concentrate develops stale, oxidized flavors that taste flat and cardboard-like. For maximum freshness, store in glass containers rather than plastic, which can absorb and impart off-flavors. Keep the container sealed as much as possible to minimize oxidation from air exposure.