Grind size controls how fast water extracts flavor from coffee. Too coarse for the method and the water runs through before extracting enough, producing a sour, thin cup. Too fine and it over-extracts into bitterness. Nearly every bad camp cup is one of these two failures.
- 1
Match grind to contact time
Longer contact needs coarser grind. A French press holds water against grounds for four minutes and wants a coarse grind. Espresso pushes water through in 25 seconds and needs a fine one. Pour-over sits in the middle. Contact time is the whole logic.
- 2
Learn the two failure tastes
Sour, thin, and watery means under-extraction — grind finer or brew longer. Bitter, harsh, and drying means over-extraction — grind coarser or brew shorter. Being able to name which one you are tasting is the entire diagnostic skill.
- 3
Use household references for size
Coarse is roughly sea salt. Medium-coarse is coarse sand. Medium is table salt. Fine is powdered sugar with a slight grit. These references are enough to get within range without any equipment.
- 4
Understand why uniformity matters
Inconsistent grind produces fines that over-extract and boulders that under-extract, in the same cup. That is why coffee can taste simultaneously bitter and sour, and it is the main reason a burr grinder beats a blade grinder or pre-ground supermarket coffee.
Hand grinders explainedBurr versus blade and why uniformity mattersRead Guide → - 5
Adjust for altitude and cold
At altitude water boils cooler, which slows extraction — grind slightly finer to compensate. In very cold conditions your brew water loses temperature fast in a cold mug, with the same effect. Both push in the same direction.
Grind by Method
| Method | Grind | Reference | Contact time |
|---|---|---|---|
| French press | Coarse | Sea salt | 4 minutes |
| Mesh dripper | Medium-coarse | Coarse sand | 3 minutes |
| Paper pour-over | Medium | Table salt | 3 minutes |
| AeroPress | Medium-fine | Between salt and sugar | 60-90 seconds |
| Moka pot | Fine | Powdered sugar, gritty | Pressure driven |
| Espresso | Very fine | Powdered sugar | 25-30 seconds |