Mold In Coffee Maker: How To Clean Coffee Maker Mold

Coffee is enjoyed by millions of Americans each and every day. So, what could be worse than going to the kitchen to make your favorite cup of Joe, only to look into your coffee maker or espresso machine and find it full of what looks like mold?

In this article, we will be covering why coffee makers become moldy in the first place, whether the types growing in there are dangerous, simple steps you can use to clean your coffee maker, how to prevent it from happening again, and a whole lot more for good measure, so keep reading.

To clean mold from a coffee maker, make a solution of equal parts of tap water to white vinegar. Place a filter into the drip area and the solution within the water reservoir. Run the machine as normal to allow the vinegar vapors to kill all mold and its spores within the machine.

Mold in coffee maker how to clean

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Coffee maker mold, why does it happen?

Mold is not picky about where it lives and breeds, as long as it has the conditions it needs to grow, rest assured that it will. Unfortunately, your coffee pot is not off limits, and in fact, it could offer the perfect circumstances for it to thrive.

Mold only needs a few things to live happily, which are:

  • A source of nutrients
  • A source of moisture
  • An ambient temperature between 60-80 degrees Fahrenheit (15.5 – 26 Celsius)

As you will see from this list above, your coffee pot (if left alone), provides the perfect habitat.

Its nutrients are either coming from the minuscule coffee grounds that may still be clinging to the side of an unwashed coffee pot, or it could be getting its sustenance from dust and other organic debris if it is growing in the water reservoir.

The moisture is fairly self-explanatory, but to elaborate, even the smallest amount of liquid left in your coffee maker is enough to create a humidity level that is acceptable for mold growth (which is anything over 55%).

Finally, fungi love temperatures between 60-80 Fahrenheit, and most American thermostats are set to between 68-76 Fahrenheit, giving the spores just the right temperatures they need to settle down and develop a colony comfortably.

What type of mold grows in a coffee pot?

There are three strains of fungi that are found most commonly within the home and potentially, in your coffee maker as well as in espresso makers, Cladosporium, Penicillium, and Aspergillus. There is a very good chance one of these would be the culprit if you found mold growing in your coffee maker.

Whilst these are the three most common molds found within a home, there are thousands of other strains and variations, so you should never assume that you are dealing with anyone in particular unless you have had it tested.

What does mold growing in a coffee maker look like?

Coffee maker mold can grow in any part of your machine but is commonly found in either the water reservoir or the pot itself.

The three common fungi mentioned above come in varying shades but are most often seen growing in black, off-white, and green patches. However, there are variants that can appear orange, red and even blue in color.

In terms of texture, you will commonly see fungi with a powdery, velvety, fluffy, grainy, or sometimes, even slimy appearance.

Can coffee maker mold make you sick?

Yes, if you were to make and drink a cup of coffee that came from a moldy coffee maker, you could very easily become Ill for one of two reasons.

If you are allergic to mold and its spores, drinking a liquid that had particles of fungi floating around in it, or breathing in spores if you disturbed the mold patch could cause any one or more of the following symptoms:

  • Itching of eyes of throat
  • Streaming eyes and runny nose
  • Coughing
  • Breathing difficulties if you have allergic asthma

The other option mold has for making you Ill is via consumption or inhalation of a type of toxin that fungi produce as a defense mechanism when it feels threatened. These mycotoxins can cause gastrointestinal discomfort, headaches, and potentially even liver damage if consumed over the long term.

It must be said, however, that if you are not allergic, ingesting or inhaling a small amount of mold is unlikely to cause any great concern, but as it can be potentially very harmful to some people, it should always be avoided and treated immediately.

How to clean mold out of coffee machines

Before you begin tackling any kind of cleanup, you need to make sure you are wearing protective equipment. A breathing mask, rubber gloves, and eye protection are recommended to prevent inhalation or contact of mold to the skin.

The process of cleaning a coffee maker is called decalcification. And whilst you’ll be removing the mold from a coffee maker, you will also be removing limescale, the crusty, white buildup you find around the water reservoir.

Once you’ve put on all your protective gear, you’re ready to get started.

Here are the things you’ll need:

  • White vinegar
  • Water
  • An abrasive sponge
  • Detergent
  • Baking soda
  • Salt

Step 1.

Make a solution of equal quantities of white vinegar and tap water. Then pour the mixture into the coffee maker’s water reservoir.

Step 2.

The vinegar will take some time to work, so add filter paper just as if you were making a brew of coffee. This will slow down the rate at which the water passes through into the coffee pot (also called a Carafe). This gives the vinegar longer to kill any stubborn mold.

Step 3.

Your coffee maker will be hot, so allow it to cool before you place another filter in and replace the vinegar solution with plain tap water in the reservoir.

Step 4.

Whilst the pot is cooled, clean it thoroughly with the abrasive sponge and detergent. Rinse with cold water to remove any detergent residue.

Step 5.

Allow the coffee maker to brew again using plain water to flush the vinegar out of the system. Make sure the pot is completely dry after you are finished cleaning it.

To make life a little easier, I’ve placed a few links below to the Amazon store so you can easily pick up some cleaning vinegar. The good news is that it’s cheap, environmentally friendly, and can be used to clean bathrooms and kitchens too.

Member’s Mark Distilled White Vinegar (US)

Aksoy Pure White Vinegar 25% ConcentrateOpens in a new tab. (UK)

How to clean a coffee maker using water instead of vinegar

Vinegar is a very powerful cleaning product, and it certainly makes short work of mildew, but it does also have a very powerful scent that sometimes can be a bit overwhelming.

If you want to remove mold from your coffee maker, and you really don’t like the scent of vinegar in your home, you have the option of using baking soda instead.

Step 1.

Make a solution with 1 cup of water, mixed with a quarter cup of baking soda.

Step 2.

Add filter paper into the machine, and brew the water/baking solution through the coffee machine. The baking powder will cause rapid oxidization, killing the fungi and their spores just as effectively as vinegar.

Step 3.

Run tap water through the coffee machine once or twice after cleaning out the baking powder solution to remove any residue, and clean the rest of the coffee machine with warm water and an abrasive sponge.

How to prevent mold in a coffee maker

Preventing mold in the first place is always easier than dealing with it once it has become settled in any appliance. Therefore it’s best to regularly take the following steps.

  1. Clean the water reservoir and coffee pot frequently, taking extra care to ensure no coffee grounds remain.
  2. Make sure after each use the coffee maker is as dry as possible, water left behind can give mold the moisture it needs to begin to grow.
  3. Give your coffee maker a deep clean at least once every two to three months.
  4. If possible, store your coffee maker in an area of the kitchen that gets natural sunlight. The sun’s UV rays kill mold and its spores, so any sunlight it can receive will make it less likely for mold to begin to grow.

How long does it take mold to grow

Mold can begin to form in any location where its needs are met within 24-48 hours.

You may be surprised to hear after using your coffee maker on a Friday morning and forgetting to clean it on the same day, you may well find mold growing within it already on Saturday afternoon, but if the circumstances are ideal (as listed above), this is quite possible.


Mold can certainly grow within coffee makers, and in certain circumstances, rapidly. Some of these molds have the potential to cause stomach upsets and other potentially serious health issues.

Using the tips and advice above, you will know how to clean, prevent it from growing in the first place, and generally understand a little more about the mold that grows in coffee machines.

Chris Walker

Chris Walker has struggled for several years with mold after buying his own property. After finding the solutions to several issues around his home, he decided to create this site in order to answer as many questions about mold and mildew as possible to help others dealing with the same problems.

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