How to clean a coffee grinder

What you need

Most of the job is done with dry tools. Water and burrs do not mix well: steel burrs can mark or rust and moisture clogs the chute with paste. Keep everything dry unless your maker says a part is washable, which usually only applies to the hopper and the grounds container.

• A stiff, dry brush (many grinders come with one) or a clean paintbrush
• A vacuum with a narrow nozzle, or a hand blower
• Grinder cleaning pellets or tablets made for burr grinders
• A lint-free cloth for the hopper and outer case
• A cocktail stick or wooden skewer for packed grounds in the chute

Weekly clean: brush the burrs and chute

A weekly brush takes about five minutes and stops old grounds mixing with fresh coffee. On many grinders the upper burr lifts out once the hopper is removed, often by turning it to the coarsest setting first. If yours does not, brush what you can reach through the throat.

1. 1

   Switch off and unplug the grinder.

2. 2

   Grind until the hopper is empty, then remove the hopper and any bean lock.

3. 3

   Lift out the upper burr if your manual shows how, and note its position.

4. 4

   Brush both burrs, working into the teeth, and vacuum loose grounds from the grinding chamber.

5. 5

   Clear the exit chute with the brush or a wooden stick. Avoid metal tools that can scratch.

6. 6

   Wipe the hopper with a dry cloth, or wash it in warm soapy water only if the manual allows, and dry fully.

7. 7

   Refit the burr at the same setting and grind a few grams of coffee to settle it before your first real dose.

Monthly clean: grinder cleaning pellets

Grinder cleaning pellets are made from food-safe grain based material shaped to pass through burrs like beans. As they grind, they absorb oils and push out packed fines from places a brush cannot reach. They are a sensible monthly step for anyone grinding oily, dark roast beans every day.

Follow the quantity on the pack, usually a capful for a home grinder. Run them through at a medium setting, then grind a small amount of coffee and discard it so no pellet residue ends up in your cup. Check that your grinder maker does not advise against pellets: a few do, and a small number of built-in grinders are not designed for them. Do not use rice. It is harder than coffee, can strain the motor and leaves starchy dust.

Note:Always unplug a grinder before putting fingers or tools near the burrs. Burrs are sharp and some motors can start if a safety switch is pressed.

Cleaning the grinder in an espresso machine

Machines with a built-in grinder follow the same idea, but the hopper and burr usually lock into the machine body. Empty the beans, unplug the machine, lift the hopper out using the lock the manual describes, then remove the upper burr by its wire handle or tab if fitted. Brush and vacuum the lower burr and chute. For a model specific walk through, see our guide to cleaning the Sage Barista Express.

If you are shopping for a new grinder and want burrs that are easy to reach, our guide to the best coffee grinders for espresso notes which models have tool-free burr removal.

When to replace worn burrs

Burrs wear slowly. Makers give replacement intervals in kilograms of coffee ground rather than months, and the figure varies widely by burr material and design, so check the manual. Signs that burrs are worn include grinding taking longer, more fine dust and boulders in the same dose, shots that run fast even at the finest setting, and chipped or rounded teeth you can see.

Replacement burrs are usually sold by the grinder maker. Fit them exactly as the manual shows, then recalibrate the grind setting, since new burrs often grind finer at the same number.

See grinders for filter coffee →

Frequently asked questions

Can I wash coffee grinder burrs in water? Usually not. Most makers say to keep burrs dry because water can cause rust and leaves paste in the chute. If your manual says a burr is washable, dry it completely before refitting.

Do coffee grinder cleaning pellets work? They do a good job of lifting oils and packed fines that a brush misses. Use the amount on the pack and grind a little coffee afterwards to clear any residue.

Can I clean a coffee grinder with rice? It is better not to. Rice is harder than coffee beans, can strain the motor and leaves starchy dust behind. Grinder pellets are designed for the job.

How often should I clean my coffee grinder? A quick brush every week and a deeper clean with pellets about once a month suits most home users. Grind dark, oily beans daily and you may want to clean a little more often.