Why and How You Should Clean Your Coffee Maker

Clean Your Coffee Maker or Risk Drinking a Morning Mix of Microbes

Learn how to clean a coffee maker.
Photo by Thomas Northcut

If you use a drip coffee maker, there's a good chance you've noticed a dark buildup on the inside of the carafe. There's even a good chance that you may have popped that glass carafe into the dishwasher from time to time. But washing the carafe isn't enough to keep your coffee maker clean. The inside of the coffee maker gets dirty too -- and there are excellent reasons to clean it regularly.

Why Clean the Inside of a Coffee Maker?

Remember biology class?

To encourage mold and bacteria to grow, you provide them with three things: organic matter (such as ground up coffee beans), warmth, and a little water.  Not surprisingly, the inside of a coffee maker is an ideal environment for growing mold, bacteria, and yeast. And while your body can handle a little muck from time to time, daily exposure to increasingly large quantities can cause illness. One study published by the National Science Foundation actually found that coffee maker reservoirs can contain high levels of potentially harmful coliform bacteria.

Meanwhile, in addition to growing less-than-delicious micro-organisms, your coffee maker is also building up mineral deposits. Calcium crystals come with tap water. The harder your water, the more calcium you're adding to your coffee. While calcium crystals won't hurt you, they don't do wonders for the taste of your coffee.

How to Clean Your Coffee Maker

Fortunately, there's no need to invest in a special tool or cleanser to keep your coffee maker free of nasty tastes and potentially harmful organisms.

All you really need is vinegar, water, soap, and a clean sponge. To clean your coffee maker:

1. Remove and dispose of any used coffee filters from the filter basket.

2. Add vinegar to the coffee maker's water reservoir until about 1/4 full. Fill the rest of the reservoir with water until full.

3. Run the coffee maker.

4. Turn off the coffee maker and let it cool for 10 minutes.

5. Run the vinegar and water mixture through the coffee maker again. Let cool another 10 minutes.

6. Run clean water through the coffee maker. Let the coffee maker cool for minutes, and repeat once more. If the vinegar odor is still present after two rinses, continue to run water through the coffee maker.

7. Hand-wash the carafe and filter basket in soapy water. You can also wash the carafe in the dishwasher.

But I Don't Want to Clean My Coffee Maker!

You can reduce the need for multi-step cleaning, but there's really no way to avoid cleaning altogether. Here are a few options:

  • Buy a water filtration system that reduces the minerals in your tap water. This will reduce the need to decalcify your pot (though, of course, you'll still be growing those pesky bacteria!).
  • Buy a self-cleaning system with a charcoal filter. These systems can reduce the need for hand cleaning, but sooner or later you'll need to pull out the vinegar.
  • Try a French press. These simple, old fashioned coffee makers make a terrific cup of coffee -- and there are no internal workings to decalcify or disinfect. On the other hand, you'll have to wash out your French press daily with plain old soapy water!