What is the best ratio for cold brew?

A 1:5 ratio (coffee to water by weight) makes a strong concentrate ideal for diluting with water, milk, or ice — a 1-litre batch needs about 200 g of coffee. A 1:8 ratio gives a lighter concentrate that some prefer to drink straight, while around 1:15 makes a ready-to-drink brew you pour and enjoy as-is with no dilution. Start with 1:5 and dilute to taste, or pick the ready-to-drink option if you do not want to dilute.

How long should cold brew steep?

Between 12 and 24 hours in the fridge. 16-18 hours is the sweet spot for most people — long enough to extract plenty of flavour without becoming bitter. Shorter steeps give lighter, more delicate flavours.

Why does cold brew taste different from hot coffee?

Cold water extracts fewer of the harsh, sour and bitter compounds that hot water pulls out, so many people find cold brew smoother and less bitter, with a mellow, chocolatey profile. The popular claim that it is "67% less acidic" comes from a coffee-equipment maker's own study and is not supported by independent testing — research at Jefferson University measured the pH of hot and cold brew at 4.85–5.13 (statistically similar). Cold brew does have less titratable acidity (which affects perceived sourness and flavour) rather than a meaningfully different pH.

How long does cold brew concentrate last?

Undiluted cold brew concentrate keeps in the fridge for up to 2 weeks. Once diluted, drink within 2-3 days. Always store in a sealed container.

What grind size should I use?

Use a coarse grind, similar to raw sugar or sea salt. Too fine a grind will over-extract during the long steep time, resulting in bitter coffee, and makes it harder to filter.

How do I dilute cold brew concentrate?

Mix concentrate 1:1 with cold water, milk, or your preferred liquid. Adjust the dilution to taste — some prefer it stronger (2:1 concentrate to water) and others lighter (1:2). Serve over ice.

BakeCalcs

Cold Brew Coffee Calculator

Calculate the right amount of coffee and water for cold brew concentrate based on your preferred ratio and batch size.

Batch Size (Water)

Total cold or room-temperature water for the batch

Steep TimeSelect the steep time for your calculation

Coffee-to-Water RatioSelect the coffee-to-water ratio for your calculation

How We Calculate This

Cold brew is made by steeping coarsely-ground coffee in cold or room-temperature water for 12-24 hours. The result is a concentrate that you dilute before drinking.

The Formula

Coffee (g) = Water (ml) ÷ Ratio
Concentrate yield (ml) = Water + Coffee g − (≈2 g × Coffee g) = Water − Coffee g — wet grounds retain roughly 2 g of liquid per gram of dry coffee, so the net loss is about 1 g per gram of coffee and scales with the dose, not a flat share of the water (about 80% of the water survives at 1:5, rising to ~87% at 1:8)
Servings = Yield × Dilution ÷ Serving size (default diluted 1:1 into 250 ml; ready-to-drink ratios are poured straight, no dilution)

Common Ratios

1:5 — Strong concentrate, best diluted before drinking
1:6 — Medium concentrate, good balance
1:8 — Light concentrate, drinkable straight or with a little ice
1:15 — Ready-to-drink, poured straight with no dilution

Frequently Asked Questions

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Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.