Coffee Grind Size Chart
Seven grind sizes, what each one feels like between your fingers, and which brewer wants it. Grind is the dial that fixes sour and bitter, so it is worth getting right.
Grinding changes one thing: how much surface area the water can reach. Finer means more surface, which means faster extraction. That is the whole mechanism.
Everything below follows from it. A method with a long contact time needs a coarse grind or it over-extracts. A method with nine seconds of contact needs a fine one or nothing dissolves at all.
The chart
Microns are approximate and vary between grinders. Use the feel description: it travels better than a number.
| Grind | Feels like | Microns | Methods |
|---|---|---|---|
| Extra fine | Icing sugar, almost powder | Under 200 | Turkish coffee in a cezve or ibrik |
| Fine | Table salt, slightly finer | 200 to 400 | Espresso, moka pot, AeroPress under a minute |
| Medium-fine | Fine beach sand | 400 to 600 | V60, Kalita Wave, phin, South Indian filter |
| Medium | Coarse sand | 600 to 800 | Drip machine, Clever dripper, siphon, AeroPress |
| Medium-coarse | Rough sand, just gritty | 800 to 1000 | Chemex, Café Solo, longer pour overs |
| Coarse | Sea salt flakes | 1000 to 1200 | French press, percolator |
| Extra coarse | Cracked peppercorns | Over 1200 | Cold brew, cowboy coffee |
Grinders disagree with each other. A number 15 on one burr set is not a number 15 on another, so calibrate by taste rather than by the dial.
How to tell your grind is wrong
Taste first, then adjust in one direction.
Sour, sharp, thin, salty, finishes too quickly. Under-extracted. The water did not get enough out. Grind finer.
Bitter, harsh, drying, hangs around unpleasantly. Over-extracted. The water took too much. Grind coarser.
The flow time tells you the same story before you taste it. A V60 that drains in ninety seconds is too coarse. One that stalls past four minutes is too fine. An espresso shot that pours in twelve seconds is far too coarse; one that drips for fifty is far too fine.
Change one step at a time and brew again. Two changes at once teaches you nothing.
Why burr grinders are worth it
A blade grinder is a propeller. It smashes beans until you stop it, which produces dust and boulders in the same batch. The dust over-extracts and tastes bitter, the boulders under-extract and taste sour, and you drink both at once. No ratio fixes that.
Burrs crush beans between two surfaces set a fixed distance apart, so particles come out close to one size. That consistency is the single biggest jump in quality available to a home brewer, ahead of the beans and well ahead of the brewer.
A decent hand grinder costs less than a cheap electric one and usually grinds better, at the cost of a minute of effort. If you are buying one thing after a scale, buy this.
Fines, and why a little grit is normal
Even good burrs produce a small fraction of very fine particles. They are unavoidable: coffee fractures unevenly along the cell structure of the bean.
Fines matter because they extract much faster than everything else and can clog a filter. That is why a French press leaves silt in the bottom of the cup, and why plunging hard forces fines through the mesh. Press the plunger slowly and stop before the bottom.
For pour over, a very small number of fines is what gives the cup body. A grinder that eliminates them entirely tends to make coffee that tastes clean and slightly hollow.
Questions
Can I use pre-ground coffee for espresso?
You can, but pre-ground espresso is ground for an average machine rather than yours, and you have no way to adjust when the shot runs fast or slow. Since grind is the main lever on an espresso machine, pre-ground removes the one control that matters.
How long does ground coffee stay fresh?
Minutes rather than days for the aromatics. Grinding multiplies the surface exposed to oxygen enormously, so a week-old grind is noticeably flat. Whole beans hold for two to three weeks after roasting.
What grind for a drip machine?
Medium, like coarse sand. If the basket overflows, go coarser. If the coffee tastes sour and the brew finishes early, go finer.
Why does my French press taste bitter even on coarse?
Usually time rather than grind. Four minutes is the steep, and the coffee keeps extracting after you plunge. Decant it into another vessel instead of leaving it sitting on the grounds.