French Press Grind Size: How Coarse, and How to Fix a Muddy Cup
Most French press recipes say "coarse" and stop there. That is a start, but every grinder numbers its dial differently, so "coarse" on one machine can be medium on another. Here is how to find the right setting on yours.
What coarse should look like
A good French press grind looks like coarse sea salt or breadcrumbs. You should see separate pieces, not powder. If you rub some between your fingers and it feels like flour, it is far too fine.
A French press filters through a metal mesh, not paper. Paper catches fine dust; mesh lets it through. That is why grind size matters so much here. Too fine, and the cup turns muddy and bitter, and the plunger gets hard to push.
Find your setting in three brews
- Start near the coarse end. On a grinder with a numbered dial, begin a few steps in from the coarsest setting. If your grinder has a guide, like the one under the lid of the Fellow Ode Gen 2, start where it suggests for French press.
- Brew the same way each time. Use the same dose, the same water and a four-minute steep. Change only the grind.
- Taste and adjust one step at a time.
- Sour, thin or weak: go one step finer.
- Bitter, dry or muddy: go one step coarser.
- Sweet, full and clean: write the number down.
Different beans want different settings. A light roast usually needs a slightly finer grind than a dark roast.
Fixing a muddy cup
If the grind looks right and the cup is still muddy, try these before you change anything else:
- Don't stir hard. One gentle stir after pouring the water is enough. Heavy stirring breaks grounds into smaller bits.
- Press slowly. Pushing fast forces fines through the mesh. Take 20 to 30 seconds.
- Pour gently and leave the last bit. The final half-inch in the press is mostly sludge. Leave it behind.
- Pour it all out once it's brewed. Coffee left sitting on the grounds keeps extracting and turns bitter.
When the grinder is the problem
If you have tried all of this and still get a cloudy, bitter cup, look at the grinder itself. A blade grinder makes powder and chunks in the same batch, and no amount of technique fixes that. A burr grinder makes a more even grind. Grinders built for brewed coffee, with large flat burrs, are designed for the most even result at the coarse end. Our comparison of grinders for French press covers five options.
Keep the burrs clean
Old grounds and oils build up in any grinder over a few weeks. That buildup can change how the grinder performs. Brush out the burrs regularly, following the maker's instructions, and your setting will stay reliable.