How to Clean a Coffee Maker

Why Coffee Makers Need Regular Cleaning

Coffee makers seem self-cleaning — hot water passes through, why would they need maintenance? Two reasons.

Mineral scale. Tap water contains dissolved minerals (mainly calcium and magnesium). When water heats up in your coffee maker, these minerals precipitate out and cling to the heating element, the internal tubes, and any spray heads. Over months, scale builds up to the point that it insulates the heating element (so water doesn't get hot enough), restricts water flow (so brewing slows down), and breaks off in flakes that show up in your coffee.

Coffee oils and bacterial growth. The water reservoir, brew basket, and carafe all accumulate coffee oils that go rancid over weeks. Damp environments (especially the reservoir) can grow mold and bacteria. A maker that hasn't been cleaned thoroughly in months produces measurably worse coffee even when you change everything else.

Most manufacturers recommend descaling every 1-3 months for moderate-use machines, monthly if you have hard water. Daily wiping and weekly washing of removable parts is also part of basic maintenance.

Daily and Weekly Cleaning

Quick habits that prevent bigger problems.

After every brew

Rinse the carafe with hot water. Don't leave coffee sitting in it for hours — old coffee residue is hard to clean. Empty the brew basket and rinse the filter holder.

Daily

Wipe the warming plate with a damp cloth. Empty and rinse the water reservoir if your machine has one (some have removable reservoirs that can go in the dishwasher).

Weekly

Wash the carafe with dish soap and hot water — the inside often develops a coffee film that builds up. Hand-wash the brew basket and filter holder. Wipe down the exterior, focusing on the spray head where water comes out (use a damp cloth or soft brush to clear any clogs in the holes).

Monthly Descaling

The big maintenance task that prevents most coffee maker problems.

What to use

White vinegar is the classic descaling agent — cheap, effective, and food-safe. Mix 1 part white vinegar with 1 part water (some makers recommend stronger 2:1 vinegar/water for very scaled machines). The downside: lingering vinegar smell that takes several flush cycles to remove. Citric acid (sold in packets at grocery stores or in bulk online) works similarly to vinegar without the smell. Use 1-2 tablespoons per pot of water. Commercial descalers (Urnex Dezcal, Affresh, Durgol) are the most expensive but most effective — formulated specifically for the temperatures and surfaces in coffee makers, no smell or aftertaste.

The descale procedure

1. Empty the water reservoir and remove any coffee, filters, or used grounds.
2. Fill the reservoir with descaling solution.
3. Run a full brew cycle (without coffee).
4. If your machine has a "descale" mode, follow that instead — modern machines pause mid-cycle to maximize contact time.
5. After the cycle, let the machine sit for 15 minutes to soak.
6. Run 2-3 full cycles with fresh, clean water to flush out all descaling solution before brewing coffee again.

Signs your machine needs descaling

Brewing takes longer than it used to. Coffee comes out cooler than before. You see white flakes in your coffee or in the carafe. The machine is making louder noises than usual. The water reservoir has a chalky white film. Any of these means descale immediately, regardless of your usual schedule.