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Coffee Makers

How to properly clean your coffee grinder

Gunk can build up inside your coffee grinder over time. Here's how to remove that buildup, whether you use a blade or a burr grinder.

Tyler Lizenby/CNET

Just like your coffee maker, the machine you use to grind the beans for your morning cup needs regular maintenance. Oils and particles cling to every nook and cranny inside, eventually leading to decreased performance -- unless you take just a few minutes to clean it out every so often.

Here's how to clean your coffee grinder.

Blade grinders

Coffee grinder
L'Equip

With blade grinders, a motor rotates two or three blades in a confined space, pulverizing almost anything you put inside it. Technically, these are not recommended for grinding coffee, as they produce very uneven grounds.

Most people use blade grinders for grinding up spices, but they can work for coffee in a pinch.

To clean a blade grinder:

  • Add roughly 1/4 cup (about 20 grams) of dry, uncooked rice to the hopper.
  • Run the grinder until the rice becomes a fine powder.
  • Dump the rice into the waste bin.
  • Unplug the grinder and wipe out the inside with a damp towel.

Repeat this process any time your grinder looks like it needs to be cleaned or starts giving off an unusual smell. (This can easily happen when grinding coffee, as the oils produced will cling to the blades and the inside of the hopper.)

Conical burr grinders

baratza-coffee-grinder-product-photos-1.jpg
Tyler Lizenby/CNET

A burr grinder is a slightly more complex contraption. Rather than chopping the beans with blades rotating at a high speed, coffee beans are fed into an adjustable fixture with an inner and outer burr. You can move the inner burr closer or further from the outer to adjust the grind size. Burr grinders give you a far more consistent grind size, which leads to a more controlled brew process.

Cleaning a burr grinder will vary by model, mainly due to different parts and construction, but it's all the same concept, even for manual hand mills. It starts with disassembling the grinder.

  • Most burr grinders hold coffee beans in a hopper. Remove this and wash it and the lid by hand.
  • With the hopper removed, run the grinder for a few seconds (if possible) to remove any remaining coffee from the burrs.
  • Unplug the grinder.
  • Next, remove any plastic or rubber parts that come in contact with coffee beans and wash those by hand as well, including the bin that catches the ground coffee.
  • Remove the inner burr. This may require a tool.
  • Use a stiff brush to knock loose any coffee grounds that may be stuck to the inner and outer burrs.
  • Use a dry cloth to wipe the inner and outer burrs to help absorb and remove any oils left behind by the coffee beans. (Do not wash the burrs with water.)
  • Allow all the hand washed parts to fully dry and reassemble the grinder.

If you would rather not disassemble your coffee grinder, you can buy grinder cleaning tablets to run through your machine. These tablets cost about $9, £9 or AU$20 for three single-use packs. They knock loose any coffee particles left behind and absorb any lingering oils.

To use the cleaning tablets, pour the recommended amount into the coffee bean hopper and pulse the grinder until the tablets have fully run through the machine. Next, take approximately 1 ounce (30 grams) of coffee grounds and run them through. Discard the coffee grounds and tablet residue and rinse out the ground coffee bin.

This cleaning process should be performed every few months to remove coffee buildup from inside the grinder, or less often if you don't use it every day.