How to clean a coffee grinder
Rancid coffee oils on the burrs stale every dose you grind. Five minutes a month keeps the grinder — and the coffee — tasting new.
Last updated: August 2026
Why grinders need cleaning at all
Coffee is oily. Those oils coat the burrs and collect in the grind chamber, go rancid within a couple of weeks, and season every fresh dose with stale flavour. Oily beans (dark roasts) accelerate it. If your coffee has developed a bitter, ashy edge that new beans don’t fix — it’s the grinder.
Monthly routine (5 minutes)
1. Run the hopper empty, then unplug.
2. Remove the hopper and take out the upper burr — on most machines (and the grinders built into Sage espresso machines) it lifts or twists out without tools.
3. Brush the burrs and chamber with a stiff dry brush; vacuum the chute and grounds path. Never use water on burrs — flash rust ruins them.
4. Wash the hopper and grounds bin in warm soapy water, dry completely before refitting (coffee oils on the hopper walls turn rancid too).
5. Refit, and run 10–20g of beans through as a purge before dialling back in.
Every few months, grinder cleaning tablets (food-safe pellets ground through like beans) clear the oils from the parts a brush can’t reach — useful for built-in grinders you can’t strip far down. Skip the rice trick: rice is harder than roasted coffee, can strain the motor and burrs, and manufacturers explicitly warn against it.
Built-in grinders (Sage, bean-to-cup)
Bean-to-cup machines hide the same burrs behind the hopper — De’Longhi and Sage both design the upper burr to be user-removable, and it’s in the manual under “cleaning the grinder”. A monthly brush-out noticeably improves shot consistency because oily burrs grind unevenly. While you’re maintaining: the brewing side needs descaling on its own schedule — grinder oils and limescale are the two separate ways a machine drifts out of shape.
Frequently asked questions
Can I clean my coffee grinder with rice?
No — it's a persistent myth. Raw rice is harder than roasted coffee, strains the motor, can chip burrs, and grinder manufacturers explicitly warn it voids warranties. Use a brush and, for deep cleans, purpose-made grinder cleaning tablets.
How often should I clean a coffee grinder?
Brush out the burrs and chamber monthly with daily use, and do a tablet deep-clean every 2–3 months — more often if you grind dark, oily roasts. Wash the hopper monthly too; oils on its walls go rancid.
Why does my coffee taste bitter even with fresh beans?
If new beans don't fix it, rancid oil residue in the grinder usually explains it — old oils season every fresh dose. A full burr clean and hopper wash typically restores the cup within a day or two of grinding through.
Can I wash grinder burrs with water?
No — burrs flash-rust. Brush them dry, vacuum the chamber, and keep water for the hopper and bin only (fully dried before refitting).
Related guides
- Best coffee machine descalers UK
- How to descale a coffee machine · Sage · De’Longhi · Nespresso
- Best coffee machines UK
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