Mold In Espresso Machine: How To Clean Coffee Maker Mold

For some, a cup of instant or filter coffee is all that’s needed to give them their caffeine boost when they wake up each day, but for others, a powerful shot of espresso is the only thing that will do.

The problem is, espresso machines can get moldy just like other coffee makers, so what do you do when you go to make your morning shot, only to find mold growing in your water reservoir and potentially in the pipe work also?

The good news is that I will be explaining how to clean your espresso machine to remove all traces of mold, how to prevent it from happening again, and even more, so keep reading!

How to clean mold from an espresso machine

Related articles

Moldy Coffee And Mycotoxins: Do You Need To Worry?
Mold In Your Coffee Maker: How To Clean It And Prevent It

Why does an espresso machine coffee maker grow mold?

Mold can grow in many locations throughout your home, and if the conditions are right in your espresso machine, then yes, mold can certainly begin to grow there.

All mold needs to grow is moisture, a source of nutrients, and an ambient temperature of between 60-80 degrees Fahrenheit.

Your espresso machine makes a great environment for mold because there is plenty of moisture from where steam has condensed and created water droplets, or within the water reservoir itself. There are also plenty of nutrients from any leftover coffee grounds that may have been missed when cleaning, or from dust that may have settled on or within the machine, and your espresso maker is no doubt stored in a warm location in your home, such as a kitchen where the temperature is just right nearly year-round.

All these factors coming together means that unless you keep a close eye on your coffee-making machinery, you could very well end up with a hot shot of moldy coffee.

What kind of mold grows in an espresso coffee machine?

The three main strains of mold that you are most likely to see growing anywhere in your coffee machine are Cladosporium, Penicillium, and Aspergillus.

These typically come in shades of black, white, grey, blue, green, and even orange or red. In terms of textures, they are often described as velvety, powdery, or even slimy in some cases.

However, there are thousands of different strains of mold, so it is very difficult to be accurate when determining which strain you are dealing with without having the mold tested in a lab.

Finally, you may also see blue or green-colored fungi growing on coffee grounds if they have been sitting in your machine for some time, this is called Trichoderma, and is usually quite harmless.

Can you get sick from mold in espresso coffee machines?

Yes, there is potential for you to become ill if you ingest or inhale mold or its spores. Whilst most molds are perfectly harmless to humans and animals, some can produce a metabolite called mycotoxins when they feel threatened.

If you were to ingest or inhale mycotoxins in small quantities, you would rarely come across any harm unless you were particularly susceptible to them. However, in the example that your coffee maker has mold in a location that was not easy to see or clean, and so you were unknowingly drinking cups of moldy coffee for several weeks, you could begin to experience any of the following symptoms:

  • Headaches
  • Nausea
  • Vomiting
  • Gastrointestinal discomfort
  • Breathlessness

Prolonged, heavy exposure of mycotoxins has also been linked to liver damage and cancer in some individuals, so you should clean mold within coffee makers as quickly as possible.

How do you clean mold out of an espresso machine?

There are two methods you can use to rid your espresso makers of mold, and the good news is that both are non-toxic, environmentally friendly, and very cheap.

The first option is to use white (distilled) vinegar, as it has a pH of 2.5 meaning it is acidic. This acidity is powerful enough to kill mold and its spores in a matter of minutes.

The second option is to use baking soda. This kills mold in a different way, as it has a pH level of 8.1, making it mildly alkaline. This will both kill the mold and dissolve the remains.

Vinegar method

In order to deep clean an espresso machine with vinegar, use the following steps:

Step 1. Create a solution of one cup white (distilled) vinegar to two cups water.

Step 2. Remove all detachable components of the machine that are safe to be cleaned.

Step 3. Using a spray bottle, pour in the water/vinegar solution and liberally spray all the components of the espresso machine.

Step 4. Leave the parts to sit for around ten minutes to allow the vinegar to do its work.

Step 5. Once dry, put the espresso machine back together again and make another solution of one cup vinegar to two cups water.

Step 6. Pump half the solution through the espresso machine, turn it off, and leave for ten minutes.

Step 7. Turn the machine back on and pump the remaining solution through.

Step 8. Disassemble the machine one last time and wash each component in warm soapy water.

Step 9. Leave to dry thoroughly before reassembling.

Step 10. Run clean water through the espresso machine several times until no scent of vinegar remains.

Baking soda method

The baking soda method is fairly similar to the above vinegar method.

Step 1. Make a solution of one tablespoon of baking soda to three cups of water.

Step 2. Using a spray bottle, spray the solution on all detachable components and leave it to sit for ten minutes.

Step 3. Clean the components with warm soapy water and leave them to fully dry.

Step 4. Reassemble the espresso machine and run a cycle of baking soda solution through.

Step 5. Run a further cycle through the machine of plain tap water to remove any baking soda solution.

How to prevent mold from growing in an espresso coffee maker

The best method to prevent mold from growing in an espresso machine is to deny it everything it needs to live, such as moisture and nutrients.

Keeping your espresso machine clean by using the methods above is an excellent way to remove any coffee grounds that mold can use for food, and keeping the water reservoir empty and dry, as well as wiping the machine down after use to reduce moisture levels will help to deprive it of the moisture it needs.

Mold can begin to grow within 24-48 hours once it settles on a surface that meets its requirements. So, making sure that no coffee grounds are left in the machine and cleaning it as soon as you are done with it gives you the greatest chance of not needing to deal with mold buildup.


Espresso machines are just as likely to suffer from mold issues as regular, drip coffee makers. Mold found growing in an espresso machine can indeed be harmful to humans, so use the cleaning and prevention methods above to reduce the likelihood of mold growing in the first place.

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.

Recent Posts