How to Clean a Coffee Maker and Prevent Bacteria Growth

Is your coffee maker hiding mold inside? Here's how to clean it

For many people, drinking coffee is such an essential part of their morning routine that they don’t feel all the way awake until they’ve had that morning pick-me-up. According to Statista, almost half of U.S. survey respondents report drinking between two and three cups of coffee per day. Roughly one-fourth of respondents say they drink one cup. Because of our obsession with coffee, the humble coffee maker can end up being one of the most important small appliances in the kitchen.

We rely on our coffee makers to produce a nice, hot cup of coffee that’s just right. We trust our coffee makers, and we don’t expect them to make a tainted cup of expensive coffee that’s not safe to drink.

But just how clean is that coffee that comes out of the machine? That depends. A better question is how clean is your coffee maker? Some people think because the coffee itself is hot, that it kills all the bacteria and their cup of Joe is automatically sanitary. But if you don’t clean your coffee maker. you could actually be drinking coffee that’s not exactly appetizing. Your machine could even contain mold or other nasty bacteria.

Moist and wet environments are ideal places for yeast and mold to grow. A study by NSF International found that 50 percent of households had yeast and mold in the reservoir of their coffee maker. When CBS News swabbed 11 household coffee makers, they found 11 different types of bacteria, including pseudomonas aeruginosa (a bacteria that grows in standing water) and enterobacter bacteria (a coliform bacteria that’s present in the human colon).

Grossed out yet? If cleaning your coffee machine isn’t a part of your chores, you may want to make it a part of your cleaning regimen.

Here’s how to properly clean your standard-drip coffee machine.

patrickhastings/123rf

What you’ll need

You don’t need anything special to clean your coffee machine, just a few items you probably already have around the house.

  • Vinegar
  • Distilled water
  • Baking soda
  • Dish soap
  • A clean sponge or gentle scrub brush
  • A clean cloth

Step 1: Remove the coffee maker’s filter

Start off by removing your machine’s reusable filter (if applicable). Then, soak the filter in a solution of distilled water and a squirt of mild dish soap for 20 minutes. Then, give it a good rinse under water to remove any soap residue. After you’ve rinsed it thoroughly, leave the filter out on a drying rack, and allow it to dry completely.

Step 2: Create a cleaning solution and run it through your coffee machine

Mix one cup of vinegar with one cup of distilled water to create a cleaning solution. For smaller coffee makers, you can use one-half cup of vinegar and one-half cup of water. Pour this solution into the water tank, and let it sit for about 20 minutes. This will help clean some of the funk that’s sitting in the bottom of the water tank.

After the 20 minute time period passes, turn on the coffee machine and brew the vinegar and water solution through your machine. Once it brews through into the pot, swirl the hot vinegar and water solution around your coffee pot, and then discard the solution.

Brew two cups of distilled water through your machine to help get rid of some of the vinegar residue. Swirl the hot water around in the coffee pot, and then empty the pot. Repeat the process until your machine no longer smells vinegary.

Step 3: Clean your machine’s exterior

Clean the exterior of the machine using a clean sponge or disinfecting wipes, baking soda, and distilled water. Use dish soap to remove any coffee stains. Then, wipe your machine with a cloth and water to remove any baking soda or soap residue.

When you finish cleaning the exterior, leave the lid off of the water tank, remove the lid from the coffee pot, and allow your machine to dry out completely.

How often to clean your coffee machine and other tips

It’s a good idea to deep clean your coffee maker using the above steps at least once a month. You should refer to your machine’s owner’s manual for additional instructions on how to clean your machine. You can also clean the removable filter and the interior of your coffee pot with mild dish soap and water after each use. Below are a few other tips to keep your coffee maker clean and sanitary.

  • It’s generally not a good idea to place your coffee pot or any other parts of the machine in the dishwasher.
  • When your machine is empty and you’re not using it, leave the lids off of both the water reservoir and the coffee pot. This allows the interior to dry completely, and it helps reduce mold and bacteria growth. Many types of mold and bacteria thrive in damp environments.
  • Avoid using harsh cleaners like bleach in your coffee machine. Even if you rinse it thoroughly, you may still be left with residue. Plus, you don’t want to damage your machine. It’s best to use a food safe cleaner on the interior of your machine.
  • Distilled water is ideal for cleaning your coffee machine because it doesn’t leave behind impurities or water stains.
  • This guide includes instructions for cleaning a standard drip coffee maker with a pot. For detailed instructions on how to clean a Keurig machine, check out our Keurig cleaning guide.

Editors' Recommendations