How To Descale a Coffee Maker

published Sep 22, 2017
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(Image credit: Joe Lingeman)

We make a lot of coffee in my house. We also have very hard water. So I often start a brewing cycle and return to pour myself a cup, only to find an alarmingly bright-red light on my coffee maker. (Luckily, it still brews the full pot!) It’s the sign telling me that it’s time to descale my machine. It’s always scary to see a red light on any machine — especially when coffee is involved! Luckily, it’s not all that hard to deal with.

Here’s how to descale a coffee maker.

What does it mean to descale a coffee maker?

First, let’s talk about hard water. Hard water has a higher mineral content (think: calcium, magnesium, and limestone) compared to soft water. These minerals can build up over time in your coffee maker, in your sink’s sprayer, in your dishwasher, and more. It’s not a big deal, but it can impact the taste of your coffee and block the holes in your fixtures and appliances. So when you descale something, you’re simply removing that buildup.

How do you know it’s time to descale a coffee maker?

If your machine has a light indicator, then the light will turn on to let you know when the machine needs descaling. If you have an older machine or a model with less bells and whistles, it might not. You don’t even need a light, though, because you’ll usually be able to see when it’s time — there will be a chalky white residue. Or again, your coffee might start to taste a little off.

I have to descale my machine a few times a year. You may have to do it more or less, depending on your machine, how often you make coffee, and the hardness of your water.

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Empty your coffee maker: Make sure the carafe is empty and clean, and that the grounds have been cleaned out of the chamber. (Image credit: Joe Lingeman)

How To Descale a Coffee Maker

What You Need

  • Water
  • Distilled white vinegar


  1. Empty your coffee maker: Make sure the carafe is empty and clean, and that the grounds have been cleaned out of the chamber.
  2. Make the cleaning solution: Fill the carafe with equal parts white vinegar and water.
  3. Pour it into the water chamber: Fill the chamber all the way to its capacity.
  4. Run half of a brew cycle: Start a brew cycle. Midway through the brew cycle, turn off the coffee maker and let it sit for an hour. Note: This is for especially bad buildups (if you haven’t cleaned your machine in ages). If you do this regularly, you can probably get away without the rest period.
  5. Finish the brew cycle: After an hour, turn on the coffee maker and let the brew cycle finish.
  6. Rinse: Pour out the vinegar-water solution and rinse the carafe.
  7. Run a water cycle: Fill the chamber with just water and let the machine run. Repeat two more times, allowing your coffee maker to cool slightly between brews. This will get rid of any lingering vinegar smell or flavor.


  • To reduce buildup, use bottled or spring water when brewing instead of softened water or distilled water.
  • If the whole machine needs attention: How To Clean a Coffee Maker