How to Clean a Coffee Maker (and Descale It Properly)

A coffee maker gets dirty in two different ways. Coffee oils build up on the carafe, basket, and anything that touches brewed coffee, and they turn rancid and bitter. Mineral scale from water builds up inside the heating element and tubing, slowing the brew and lowering the temperature. Regular washing handles the first problem; descaling handles the second. Here's how to do both, how often, and what's different for pod machines, espresso machines, French presses, and moka pots.

How Often to Clean

Moist, dark reservoirs are a real problem: a household germ study by NSF International found yeast or mold in about half of the coffee maker reservoirs it tested. Leaving the lid open to dry makes a big difference.

Daily Coffee Maker Maintenance

1. Throw away the grounds and filter as soon as the coffee is done.
2. Rinse the brew basket and carafe with hot water.
3. Leave the reservoir lid and basket open so everything dries.
4. Don't leave the carafe on the warming plate for hours — burnt coffee bakes onto the glass.

Deep Cleaning Your Coffee Maker: Step-by-Step Guide

Do this every week or two:

1. Unplug the machine and let it cool.
2. Remove the carafe, brew basket, and any removable filter holder.
3. Wash them in warm, soapy water with a soft sponge. Many carafes and baskets are dishwasher-safe — check the manual.
4. For stubborn brown stains in a glass carafe, add a tablespoon of baking soda and a little warm water, swirl, and scrub gently. Rinse well.
5. Wipe the reservoir, lid, shower head (where water drips out), and warming plate with a damp cloth.
6. Let everything air-dry before reassembling.

How to Descale Your Coffee Maker

Signs you need to descale: brewing takes longer than it used to, the machine is louder, coffee isn't as hot, or you see white, chalky deposits.

First, check your manual. Some manufacturers specify a descaling product, and a few advise against vinegar. If your machine has a "clean" or "descale" cycle, use it.

With white vinegar (most basic drip machines)

1. Fill the reservoir with equal parts white vinegar and water.
2. Put an empty paper filter in the basket and start a brew cycle.
3. Halfway through, switch the machine off and let it sit for 30–60 minutes.
4. Switch it back on and finish the cycle. Discard the liquid.
5. Run 2–3 full cycles of fresh water to flush out the vinegar taste and smell.

With citric acid or a commercial descaler

Citric acid is nearly odorless and rinses out more easily than vinegar. Follow the product's dosing instructions (for plain citric acid powder, a common starting point is about 1 tablespoon per liter of water), run it through as above, and flush with 2–3 cycles of fresh water.

Cleaning Different Types of Coffee Makers

Pod machines (Keurig and similar)

• Use the machine's descale mode with the manufacturer's descaling solution or vinegar, as the manual allows.
• The entrance and exit needles clog with grounds. Carefully clear them with a straightened paper clip (unplugged, following the manual's instructions).
• Wash the pod holder and drip tray weekly, and empty the reservoir rather than leaving water sitting for days.

Espresso machines

• After every use: purge and wipe the steam wand immediately — dried milk blocks the tip. Flush the group head for a few seconds.
• Weekly: if your machine has a three-way solenoid valve (most machines with a portafilter and a pressure-release after the shot do), backflush with a blind basket and espresso-machine detergent. Scrub the group gasket and shower screen with a group brush.
• Descaling: follow the manual exactly. For boiler machines, many manufacturers and technicians recommend preventing scale with properly filtered or softened water rather than frequent descaling, since descaling can loosen scale that then clogs valves.

French press

Disassemble the plunger (the mesh, spring plate, and cross plate unscrew) every week or two and wash each piece — grounds and oils hide between the layers. Don't pour grounds down the sink; they build up in drains.

Pour over drippers

Rinse after each use and wash with soapy water every few days. Rinse paper filters before brewing, and store them sealed so they don't absorb odors.

Moka pots

Most are aluminum. Rinse with hot water and dry completely after each use; avoid the dishwasher, which discolors and corrodes aluminum. Use mild soap only occasionally, and replace the rubber gasket when it hardens or cracks.

Common Coffee Maker Cleaning Mistakes

• Not rinsing after descaling. Leftover vinegar or descaler will flavor several pots.
• Using bleach or harsh cleaners inside the water path — they're hard to flush out and can damage seals.
• Leaving water in the reservoir for days. Refill with fresh water daily.
• Putting aluminum parts in the dishwasher.
• Using abrasive pads on non-stick warming plates or plastic parts.

Prevent Scale in the First Place

Scale comes from minerals in hard water. A simple pitcher or tap filter reduces how often you'll need to descale and usually makes better-tasting coffee too. Avoid distilled water for brewing, though — coffee needs some minerals to extract properly, and some machines rely on minerals for their water-level sensors.

Clean equipment is only half the equation for better coffee. For the other half, see our grind size guide.