Your grinder touches every bean you brew, and coffee oil goes rancid in weeks. A grinder that's never been cleaned is seasoning every fresh bag with last quarter's stale residue. The fix takes ten minutes a month.
Know your enemy: oils and fines
Two things accumulate: fines (powder packed into crevices and chutes — flow problems, dose drift) and oils (a sticky film on burrs and chamber walls that oxidizes rancid — the "why does every coffee taste slightly the same and slightly off" culprit). Dark oily roasts accelerate both dramatically.
The monthly brush-out (every grinder)
Unplug. Empty the hopper. Remove the outer burr — on a Baratza Encore or Fellow Ode this is tool-free and takes seconds. Brush burrs and chamber with a stiff brush (a clean paintbrush works), vacuum the chute and chamber — vacuum, never blow: compressed air drives fines deeper and into motor bearings. Reassemble. Done in ten minutes, and espresso users should expect their next few shots to need a small re-dial.
The quarterly deep clean: grinder pellets
Grinder cleaning pellets (Grindz and similar) are food-safe starch tablets you grind through like beans — they absorb oils and scour fines from places brushes can't reach. Run a dose, then a small sacrifice-dose of real beans to purge, and re-dial. This is the only safe way to clean where you can't see. Never grind rice — it's harder than coffee, strains motors and voids warranties (Baratza says so explicitly).
Hand grinders
Same ritual, easier access: unscrew, brush, reassemble — 1Zpresso and Timemore designs come apart in a minute. No water, ever, anywhere near burrs: flash rust on carbon steel burrs is a one-mistake lesson.
What never to do
Water or soap in the burr chamber. Compressed air. Rice. Dishwashers, obviously. And don't ignore the hopper — wash it (fully dried before refitting): its walls carry the oldest, rancid-est oil film in the whole machine. Notice your cups getting sweeter afterward? That's not placebo — see why stale oils flatten flavor.
