The dose from the grinder varies shot to shot

Grinding the same amount by time or by the same number of turns produces a different weight of coffee each time.

Applies to: Espresso machine, Espresso

Likely causes and adjustments

Try one adjustment at a time so you know what actually changed the result. Start with the first cause below — if it doesn't help, reveal the next.

Cause 1 of 3 · Commonly the cause
Grinding by time rather than by weight
Are you dosing by a timer rather than a scale?
Seconds are a proxy for grams, and the relationship shifts with grind setting, bean age and roast. Weigh instead.

Step-by-step guides to the skills this problem comes from.

Single dosing a grinderGrind exactly the beans you weighed for this brew, with as little left inside the grinder as possible.