Grinder adjustment is simple and easy to do badly.
Move in small steps
Espresso needs very fine resolution. One click or one number at a time.
The difference between a 22-second shot and a 32-second one is often two steps. Jumping five will overshoot in both directions and teach you nothing.
For filter, steps can be larger — the tolerance is wider.
Purge after every change
A grinder retains grounds from the previous setting in the chute and burr chamber.
Run 3 to 5 g through and discard it after adjusting, before judging the change. Otherwise the first dose is a mixture of both settings, and it will behave unpredictably.
This is the single most common mistake in dialling in.
Adjust while running, on some grinders
Many stepless espresso grinders — and most bean-to-cup machines — require adjustment with the burrs turning, because moving them under a static load of beans can jam or damage them.
Check the manual. It will say, and it matters.
Direction
Finer slows the flow and raises extraction. Coarser speeds it and lowers extraction.
On most grinders, turning the collar towards a lower number or clockwise is finer, but there is no universal convention.
Finding zero
Some grinders benefit from re-zeroing: with the hopper empty, close the burrs until they just touch and chirp, then back off. That is your reference point.
Do it gently — burrs touching hard damages them.
Last reviewed 8 August 2026