How to clean a coffee grinder: burr and blade grinders

Step by step: how to clean a coffee grinder

Safety first. Unplug the grinder before you touch the blades or burrs. Blades and burr edges are sharp, so handle them by the edges and brush, do not wipe with bare fingers.

1. 1

   Empty the beans and grind the chamber clear

   Remove the bean hopper or tip out any beans left in it, then run the grinder until nothing more comes out. Many burr grinders let you lock the hopper closed and lift it off, so you can pour the beans back into their bag. Unplug the grinder before going further.

2. 2

   Wash the hopper and grounds bin

   Wash the bean hopper, lid and grounds container in warm, soapy water and rinse them well. Coffee oil turns rancid and coats plastic with a brown film you can feel. Let them dry completely; water and grounds together make paste.

3. 3

   Remove the top burr

   On most burr grinders the upper burr lifts out by a wire handle or a twist. Note how it sits so you can put it back at the same setting. Leave the lower burr in place unless your manual shows how to remove it.

4. 4

   Brush the burrs and the chute

   Brush both burrs with a stiff, dry brush until the teeth look metal-colored again, and brush out the grind chute where grounds pack. A vacuum with a brush tip or a short blast of compressed air clears the fine dust. Do not wash burrs in water.

5. 5

   Clean a blade grinder

   For a blade grinder, unplug it, brush the grounds out of the bowl and around the blade, then wipe the bowl and lid with a damp cloth. If the bowl comes out, wash it in warm soapy water. Never put the motor base in water.

6. 6

   Wipe the outside

   Wipe the housing with a damp cloth to remove coffee dust and fingerprints, then dry it. Skip abrasive pads, steel wool and alkaline cleaners; Breville says they can damage the surface.

7. 7

   Reassemble and season

   Once every part is dry, put the top burr back, reattach the hopper, and grind a small amount of coffee and throw it away. That clears any remaining dust and coats the burrs, so the next dose is consistent.

Burr grinder vs blade grinder: how cleaning differs

Burr grinders need dry brushing and occasional disassembly; blade grinders are a quick wipe. The difference comes from how they grind: burrs crush beans between two toothed rings, which pack grounds into tight spaces, while blades chop in an open bowl.

KitchenAid’s grinder guide notes that blade grinders have fewer parts and wipe clean in a few steps, and that burrs should stay dry. The Breville Smart Grinder Pro manual adds that grinder parts should not go in the dishwasher.

Should you clean a coffee grinder with rice or tablets?

Use rice only in a blade grinder, and use grinder cleaning tablets in a burr grinder. Both work the same way: they grind into a dry powder that soaks up stale coffee oil and carries it out of the chamber.

Breville’s grinder cleaning guide suggests running uncooked rice through a blade grinder to remove deep-set oils, and warns that rice in a burr grinder can damage the machinery. Cleaning tablets made for grinders are formulated to break up without straining the burrs. Follow the package directions, which usually means grinding a dose at a medium-coarse setting, then grinding a small amount of coffee to purge any tablet residue before your next real dose.

Tablets save you from taking the grinder apart, but they do not replace a full brush-out every month or two, especially if you grind fine for espresso.

How do you know your grinder needs cleaning?

The coffee starts tasting stale or bitter even with fresh beans, or the grinder starts behaving differently. Breville lists these signs:

• Grounds look off-color after you switch to a different bean.
• The grinder makes unusual noises or grinds more slowly.
• The grind setting is hard to adjust.

Grounds that clump or spray out of the chute instead of falling cleanly are another clue. Dark, oily roasts and fine espresso grinds build up fastest. If you also grind spices, keep a separate blade grinder for them; spice oils carry over into coffee. Clean the grinder on the same day you descale your machine, using our guides to cleaning a coffee maker or a Breville espresso machine.

Mistakes to avoid

• Rinsing burrs under the tap, which can rust them and turns leftover grounds into paste.
• Running rice through a burr grinder.
• Putting the hopper or burrs in the dishwasher when the manual says hand wash or brush only.
• Reassembling before parts are fully dry.
• Brushing the burrs while the grinder is still plugged in.
• Forgetting where the top burr sat, then wondering why the grind changed.