Coarse — even coarser than for French press. With a contact time of 12–24 hours, a fine grind would lead to severe over-extraction and bitterness. The ideal consistency is like coarsely cracked pepper.

What grind size do I need for cold brew?

Coarse — even coarser than for French press. With a contact time of 12–24 hours, a fine grind would lead to severe over-extraction and bitterness. The ideal consistency is like coarsely cracked pepper.

Why this is the case

Cold brew is the brewing method with the absolute longest contact time: 12 to 24 hours. The coffee and cold water sit together overnight — making it an extreme immersion brew. The low water temperature significantly slows down the extraction process, but the enormous duration of the steep more than compensates for it.

To achieve a balanced cup of coffee with such a long brewing time, the grind size must be correspondingly coarse. Large particles have a smaller relative surface area, which means the extraction happens much more slowly. This counterbalances the long steep time and prevents the cold brew from becoming bitter, harsh, or over-extracted.

The ideal consistency is like coarsely cracked black pepper or small pebbles. It should be noticeably coarser than a French press grind — sitting at the absolute coarsest end of the grind spectrum. The individual particles should be highly visible to the naked eye and feel very chunky when rubbed between your fingers.

Pre-ground coffee from the supermarket is almost always too fine for cold brew — it is generally calibrated for standard drip coffee machines. If you use standard medium grounds for cold brew, the result will be a bitter, over-extracted liquid that lacks the signature smoothness and sweetness that cold brew is known for. If you don’t own a grinder, you should ask your local roaster to grind the beans extra coarse and explicitly state it is “for cold brew.”

A basic rule of thumb: the longer the steep time, the coarser the grind. If you only plan to steep for 12 hours, you can grind slightly finer. If you opt for a full 24 hours, you need to go extra coarse. By tweaking the grind size and the steep time, you can perfectly control the intensity of your cold brew.

In practice at Green Wall Coffee

At Sophienstraße 27, we make our cold brew using the absolute coarsest setting our grinder allows. We steep it for exactly 18 hours and then filter it through paper to ensure a perfectly clean cup. The result is a mild, naturally sweet cold brew that shines without any added sugar or milk. During the summer, it’s one of our most popular drinks.

Related questions

• How to make cold brew at home?
• How long does cold brew need to steep?
• What grind size do I need for French press?

For more depth on the subject, check out our V60 pour-over guide. Or visit us at Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.