What grind size is ideal for French press?
Coarse — like coarse sea salt. Too fine leads to muddy coffee and a plunger that's hard to push. Pre-ground supermarket coffee is almost always too fine for a French press.
Why that is
The French press filters with a metal mesh — not paper. The mesh has significantly larger pores than a paper filter. Anything finer than the mesh will end up in your cup. That's why the grind size is more important for the French press than for almost any other brewing method.
Ground too fine: The metal mesh cannot hold back the fine particles. The result: muddy, cloudy coffee with sediment in the cup. Furthermore, fine particles extract faster — combined with the long contact time (4 minutes), the coffee quickly becomes over-extracted and bitter. Practical indicator: The plunger requires a lot of force to push down because the fine coffee grounds clog the mesh.
Ground too coarse: The water has too little contact area. The coffee becomes under-extracted — thin, sour, watery. The plunger slides down with zero resistance.
Correct coarse grind: The particles are the size of coarse sea salt or breadcrumbs. The plunger can be pushed down with light, even pressure. The coffee has body, but no mud.
Pre-ground coffee from the supermarket is almost always set to a filter coffee grind size — medium to medium-fine. That is too fine for a French press. If you can't choose your own grind size, you won't get optimal results with pre-ground coffee. A simple manual grinder with an adjustable grind setting (€30–50) solves the problem and simultaneously improves freshness.
Guide for different grinders: On most manual grinders, the French press range is at the coarser settings; on electric grinders, it's usually in the upper third of the dial.
In practice at Green Wall Coffee
At Sophienstraße 27, we gladly pre-grind coffee to the right size for guests who use a French press at home. Bring your bag in and I'll dial in the correct grind size — then you'll see just how coarse "coarse sea salt" really looks.
Feel free to drop by for a coffee — Green Wall Coffee, Sophienstraße 27 in Berlin-Lichtenberg, Mon–Fri 8am–5pm and Sat 10am–5pm.
Further reading
In-depth article: Pour-Over Guide (V60)
Related questions:
- Why does my French press coffee taste muddy?
- Should I plunge the French press immediately after 4 minutes?
- Can I use the French press for tea too?
Also relevant:
- What grind size do I need for French press? — Grinding & Grind Size
- Can I make cold brew in a French press? — Cold Brew & Iced Coffee
All questions in this topic: French Press