Grinder produces inconsistent grounds
Ground coffee looks uneven, with a visible mix of very fine dust and larger fragments at the same setting, or the same setting produces noticeably different results from one grind to the next.
Applies to: Espresso machine, V60 (pour-over), French press
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 4 · Commonly the cause
Blade grinder rather than burr grinder
Is this a blade (chopping-blade) grinder rather than a burr grinder?
Blade grinders chop unevenly by design rather than crushing to a set gap; a burr grinder is the main fix if consistency matters for your brewing method. See choosing a grinder.
What to change
Specific adjustments for this symptom, with what each one trades off.
Learn the technique
Step-by-step guides to the skills this problem comes from.