Cold Brew Coffee Calculator

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.

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.

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.

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.

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.

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.