Mold In Coffee Maker: How To Clean In 5 Simple Steps

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? Obviously, you’ll need to clean out your coffee maker before you brew any more.

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.

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

Mold in coffee maker how to clean

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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.

As an added bonus, 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 vinegarOpens in a new tab. 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.

How to clean a coffee maker using baking soda 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 sodaOpens in a new tab. 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. Empty the water reservoir after each use, as standing water can become an easy place for mold to grow.
  3. 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.
  4. Give your coffee maker a deep clean at least once every two to three months.
  5. 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.
  6. Use filtered water to lessen the amount of natural minerals available for mold to use as sustenance.
  7. Clean the outside of the machine once every few weeks to prevent dirt and grime buildup that fungi and mold can consume.
  8. Replace filters frequently, if your machine has a reusable filter, be sure to clean it regularly, with a deep clean once every month.

Can you save a moldy coffee maker?

In most cases, yes, you can save a moldy coffee maker by thoroughly cleaning it with vinegar as this will effectively kill the mold. However, it is important to remember to clean every part of the machine, or the mold will return. Cleaning valves, seals, and all components is important to prevent regrowth.

Just because your coffee maker had mold in it initially does not mean it now needs to be thrown away as long as you follow the guidance suggested above. The exception to this rule would be when the growth has become so extensive that the entire machine is affected and there may be mold growing in internal parts.

In this case, it may be better to discard the machine and purchase a new one. This is rarely the case though, as you will often spot the growth before it has had a chance to grow to this extent.

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 needsOpens in a new tab. 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 (15.56 – 26.67 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 60%Opens in a new tab.).

Finally, fungi love temperatures between 60-80 Fahrenheit, and most American thermostats are set to between 70-75 FahrenheitOpens in a new tab., giving the spores just the right temperatures they need to settle down and develop a colony comfortably.

How long does it take mold to grow

Mold can begin to form in any location where its needs are met within 24-48 hoursOpens in a new tab..

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.

There are several factors that dictate the speed at which mold can grow in your coffee maker, which include:

  • The amount of sunlight it is exposed to
  • The temperature
  • The amount of airflow around the machine
  • The ambient humidity of the room it’s stored in

Sunlight exposure

The more natural sunlight the machine is exposed to, the harder mold will find it to grow. This is because the sun’s rays emit UV (ultraviolet) radiation, which inhibits the growth of fungiOpens in a new tab. and bacteria. It also damages the DNA of the mold, preventing it from being about to reproduce and spread.

The warmth of the sun also has a drying effect, reducing the amount of moisture on the surfaces the mold is trying to grow on, taking away its source of hydration. This is why mold is most frequently found growing in damp and dark places.

So, the more natural sunlight your machine is exposed to, the less likely mold is to grow on or in it.


Mold strains can grow happily through many temperature ranges, as some have adapted to thrive in cold temperatures, and some in very warm temperatures. However, the temperature range that mold grows at its fastest, is between 60 and 80 degrees Fahrenheit (15.56 – 26.67 Celsius).

You can of course choose to not put on your central heating, but this is of course not very practical. Instead, you are better off ensuring that all of its other needs, such as moisture and nutrients are taken away to prevent its growth.


Airflow simply refers to the amount of movement of air within a space, and without fresh air flowing through a room, stale and moisture-laden air is free to build up and settle on cooler surfaces (known as condensing).

When the droplets of water within the air start to condense on a surface, mold, and fungi can use it as a source of hydration and can begin to grow. The more hydration mold has, the faster it can grow, so by ensuring there is plenty of airflow by opening windows and doors, stale, moisture-laden air is driven out and is replaced by fresh, dry air, taking the mold’s source of hydration with it.

Ambient humidity levels

The amount of moisture within the air, (known as humidity), can play a big part in the rate at which mold can grow. The lower the overall humidity, the less chance of condensation, and the harder it is for fungi to get their hydration, the higher the rate, the easier it is and the faster it can grow.

The ambient humidity levels that allow mold to grow at its fastest is between 70-80%Opens in a new tab., so as long as you can keep levels below 70%, you will be able to significantly reduce the rate at which it can grow and form on your coffee machine or any other surface within your home.

Keeping humidity levels low can be tricky, especially in some states that have year-round high humidity levels, such as Florida or LouisianaOpens in a new tab. for example, but there are measures you can take, such as increasing the amount of airflow through the property to drive out moist air, making use of dehumidifiers, fixing any leaks and using air conditioning to dry the air.

What type of mold grows in a coffee maker?

There are several strains of fungi that are found most commonly within the home and potentially in your coffee maker as well as in espresso makers, these include CladosporiumOpens in a new tab., PenicilliumOpens in a new tab., CladosporiumOpens in a new tab., FusariumOpens in a new tab., and AspergillusOpens in a new tab.. 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 some of the most common molds seen, 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.

People are often more concerned about finding a particular type of mold growing in their home or within their appliances, black mold being the most common example of this. In reality, all mold strains should be treated with caution during removal, as even the less toxic strains can still cause symptoms in those susceptible to their spores.

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 mold in a coffee maker 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 they feel threatened. These mycotoxinsOpens in a new tab. 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.

Is mold in a coffee maker dangerous?

Moldy coffee makers certainly can be dangerous, as ingesting mold or its spores can cause serious health complaints, sometimes even life-threatening in very rare instances (as listed above). Many of the strains that grow can produce mycotoxins which can be very harmful if ingested, and even the strains that do can cause issues.

Whilst there is the possibility of these symptoms appearing, this is uncommon, and in most cases, as long as the coffee maker is cleaned promptly after the mold was discovered and little to no fungi was accidentally ingested, there should be little danger.

What if you accidentally drank coffee from a moldy coffee maker?

Ok, so the worst scenario has occurred, you’ve finished your cup of morning coffee and noticed that the machine you just made it in has mold growing in it, what are you supposed to do now?

Firstly, the good news is that you have little to worry about, as long as you have no allergies to mold or its spores and you are not feeling any immediate symptoms coming on, you will probably be fine.

Over the next few hours to days, you should keep a close eye on how you are feeling, if you start feeling ill or begin to experience any symptoms, it is best to seek medical advice just to be on the safe side.

If you begin to cough, have breathing difficulties, develop a rash, or any gastrointestinal issues, you should seek medical advice immediately, but once again, this is rare.

Over to you

I really hope this article has given you some guidance on how to clean mold out of a coffee maker and stop it from growing back. Now I’d like to turn it over to you though, have you ever drank coffee out of a moldy coffee maker? Do you have any extra tips you think should be in this article? If so, please leave a comment below and I’ll get back to you ASAP.

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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