Grind size is the biggest lever in coffee: it decides how fast water moves through the bed and how much flavor it collects on the way. Learn to read it and every brewer in the cupboard improves.
Coarse: cold brew and French press
Think breadcrumbs. Long steeps need slow extraction, and big particles keep twelve patient hours from turning muddy. If your press cup has sludge, your grind is too fine, not your filter too old.
Medium: pour-over and drip
Coarse sand that still flows through your fingers. This is the pour-over window – fine enough to extract in three or four minutes, open enough that the water never backs up in the cone.
Fine: espresso and stovetop
Table salt heading toward flour. Espresso squeezes extraction into thirty seconds, so the water needs all the surface area it can get. Half a step here changes a shot more than any other variable on the bench.
Why burrs beat blades
A blade chops beans into everything from boulders to dust, and the dust over-extracts while the boulders under-extract – a bitter and sour cup at once. Burrs crush to one size, which is the entire secret of tasting what a roaster intended.
