Calculate the perfect cold brew coffee ratio for concentrate and ready-to-drink. Covers steeping time, dilution, yield, and batch sizing for jars or pitchers.
Cold brew coffee is made by steeping coarsely ground coffee in cold or room-temperature water for 12-24 hours. The result is a smooth, low-acid, naturally sweet concentrate that can be diluted to taste and lasts 1-2 weeks in the fridge. The key variable is the coffee-to-water ratio during steeping, which determines whether you're making a concentrate (to be diluted) or a ready-to-drink brew (to be served as-is).
The most common cold brew ratio is 1:5 for concentrate (1 gram of coffee per 5 grams of water). This produces a strong, syrupy extract that's typically diluted 1:1 or 1:2 with water, milk, or ice before drinking. Ready-to-drink cold brew uses a weaker 1:8 to 1:12 ratio, brewed to drinking strength without dilution. The sweet spot for most people is a 1:5 concentrate diluted 1:1, which results in the equivalent of a 1:10 brew — balanced, smooth, and versatile.
This calculator handles both approaches: enter your desired batch volume, choose concentrate vs. ready-to-drink, and it calculates the exact coffee and water amounts, plus yields after dilution. It accounts for the coffee grounds absorbing water (about 2× their weight), so the actual yield is always less than the water you start with.
Cold brew ratios are non-intuitive because you make a concentrate and dilute it. This calculator handles the math so your batch comes out perfectly every time. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain. Use this clarification to avoid ambiguous interpretation. Align this note with review checkpoints.
Coffee (g) = Water (g) ÷ Ratio. Concentrate: ratio 1:4 to 1:6. Ready-to-drink: ratio 1:8 to 1:12. Water absorbed by grounds ≈ Coffee (g) × 2. Yield = Water − Absorbed. Final volume after dilution = Yield × (1 + Dilution Ratio).
Result: 200g coffee, 1000g water → 600mL concentrate → 1200mL after 1:1 dilution (8 servings)
1000g water ÷ 5 = 200g coffee. Grounds absorb 200 × 2 = 400g water. Yield: 1000 − 400 = 600mL concentrate. Diluted 1:1: 600 + 600 = 1200mL = ~8 servings of 150mL.
**Concentrate (1:4 to 1:6):** Thick, strong, syrupy. Must be diluted before drinking. Versatile — mix with water, milk, ice, or use in cocktails. Stores longer (2 weeks). More efficient use of fridge space. **Ready-to-drink (1:8 to 1:12):** Brewed to drinking strength. Pour and serve over ice or straight. Simpler (no dilution step) but less versatile and shorter shelf life. Takes more fridge space per serving.
Cold water extracts different compounds than hot water. **What cold brew extracts well:** Caffeine (nearly equal to hot), sugars, chocolate/caramel notes, nutty flavors. **What cold brew extracts poorly:** Bright acidic compounds, delicate floral notes, certain fruity esters. This is why cold brew tastes smoother and less acidic than hot coffee — it's literally missing the acidic compounds that hot water dissolves. For some beans (chocolatey, nutty origins like Brazil or Colombia), cold brew is ideal. For bright, fruity beans (Ethiopian, Kenyan), hot brew showcases the flavors better.
**Mason jar method (beginner):** 32 oz mason jar + fine mesh sieve. Simple, cheap, produces 2-4 servings. **Pitcher method (medium batch):** 64 oz pitcher + nut milk bag or cheesecloth. Good for 6-10 servings. **Toddy/dedicated brewer (large batch):** Purpose-built cold brew systems with felt filters produce the cleanest concentrate. 12+ servings per batch. **French press:** Works great for cold brew! Fill with coarse grounds and cold water, steep, then press. Built-in filtration.
1:5 for concentrate (dilute before drinking) or 1:8 for ready-to-drink (serve as-is over ice). Most people prefer the concentrate approach because it's more versatile — you can dilute to any strength.
12-18 hours at room temperature, or 18-24 hours in the fridge. Under 12 hours tastes under-extracted and grassy. Over 24 hours can become bitter and harsh. The sweet spot for most people is 16-18 hours in the fridge.
Cold water is a less efficient solvent than hot water, extracting about 70-85% as many compounds. The higher coffee-to-water ratio compensates. But you dilute the concentrate, so actual coffee per cup is similar to hot brew.
Undiluted concentrate lasts 2 weeks in the fridge. Once diluted, it lasts 2-3 days. The concentrate is shelf-stable longer because the higher concentration inhibits bacterial growth.
Use coarse or extra-coarse grind only. Fine grind will over-extract during the long steep, creating bitter, muddy cold brew. Coarse grind (like sea salt texture) produces the smoothest result.
Over-steeping (>24 hours) or too-fine grind are the most common causes. Use extra-coarse grind and don't steep longer than 20 hours. If it's still bitter, try a 1:6 or 1:7 ratio (less coffee) or reduce steep time to 14-16 hours.