12–24 hours. 16 hours in the fridge is the sweet spot. Shorter gets watery, longer gets bitter. Prepare it in the evening, filter it in the morning — then you have fresh cold brew for breakfast.

How long does cold brew need to steep?

12–24 hours. 16 hours in the fridge is the sweet spot. Shorter gets watery, longer gets bitter. Prepare it in the evening, filter it in the morning — then you have fresh cold brew for breakfast.

Why that is

Cold water extracts much slower than hot water. What happens in a V60 in 3 minutes takes 12–24 hours in cold brew. The long steep time compensates for the low temperature — but only up to a certain point.

Under 12 hours: Under-extracted. The coffee tastes thin, watery, and lacks body. The pleasant sweet and chocolatey aromas haven’t had enough time to dissolve.

12–18 hours (Sweet Spot): Balanced extraction. Sweet, gentle, full-bodied. Most flavor compounds have dissolved, while bitter compounds have not yet. 16 hours is a reliable standard.

18–24 hours: Stronger, more intense, slightly more tart notes. Works well for concentrates that will be heavily diluted.

Over 24 hours: Over-extracted. Bitter, woody, astringent notes. The gentle cold brew character is lost.

Fridge vs. Room Temperature: In the fridge (4–8 °C) the coffee extracts slower — here, 14–18 hours are ideal. At room temperature (20–25 °C) it goes faster — 8–12 hours are sufficient. The fridge is more hygienic and produces a cleaner flavor, because fewer undesirable compounds are dissolved.

Grind size and steep time are connected: A coarser grind size tends to need a longer steep time. If you grind finer (medium-fine), you can shorten the steep time to 10–14 hours — but be careful to avoid over-extraction and a muddy result.

Practical tip: Prepare it in the evening before going to bed, filter it in the morning. A 16-hour overnight cold brew is the most straightforward way to get good cold coffee.

In practice at Green Wall Coffee

At Sophienstraße 27, we steep our cold brew in the evening for 16 hours in the fridge. That is consistent and reliable. On particularly hot summer days, it sells out faster than we can produce it.

Related questions

• How to make cold brew at home?
• What coffee-to-water ratio do I need for cold brew?
• Which beans are best for cold brew?

Come visit us at Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.