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Can Coffee Beans Mould? 

Fruit, grains, vegetables, bread and cheese, are some of people’s most popularly consumed and favourite food types. While we’d love to enjoy our top-quality food, sometimes they fall victim to predilection from a fungus called “mould”. It’s essential to keep most of our stored food dry, especially during rainy periods.

coffee beans mould

The same goes for coffee beans also. Many might think that coffee beans don’t get afflicted by mould, but they do. This article will better explain what you need to know about moulds concerning your coffee beans. How to keep them from ruining your beans and coffee, and what to do if you ever find your coffee beans mouldy.


What are Moulds?

Moulds are a type of fungi that produce spores. They are multicellular organisms consisting of roots, a stalk and spores. Just like trees, the roots are for attachment. They attach to the food substance they afflict. The stem is the body, and the spores are similar to flowers growing at the extremities of the stalks.

Air, insects and sometimes water transport the spores. When clumped together, they’re easily visible to the human eye. A humid and warm environment is favourable for moulds to grow in. Moulds also survive on foods with an acidic nature, such as some fruits, salted meats, tomatoes and even coffee beans. You could even find some in refrigerators despite being able to thrive in warm environments.


Do Coffee Beans Get Moulds?

Yes, coffee beans could get mouldy. Like most if not all types of food, coffee could have moulds when improperly stored and processed. This improper storage and processing could harm your health, limiting any advantage coffee beans might bring to the table.


Where Do Moulds Come From?

A favourable condition for the growth of mould is moisture. Likewise, water is essential for plant growth, or in this case, all coffee plants. This is why most coffee plants are grown in tropical regions. Coffee is slightly acidic. It has a pH of range 5.2-6.9. Moulds thrive in a pH environment between the range of 6-7.

This proximity in pH ranges between coffee and a favourable growth environment for mould also contributes to the appearance of moulds. These two factors, moisture and pH, associated with coffee beans, are required to grow certain moulds. As a result, coffee bean manufacturers must utilise high-end methods and equipment to store and process the coffee beans.


How Does It Affect Coffee Beans?

At harvest, sometimes, fresh green coffee beans aren’t dried properly. This could be a result of cheap or low-standard processing drying equipment. Other times, even with high-end equipment, manufacturers could neglect adequately cleaning and maintaining their equipment. The fungi then start to grow in these situations. When the fungi aren’t killed off by simply roasting the beans, it’s possible to have them still present during their shelf lives.


Repercussions of Mouldy Coffee Beans

The moulds afflicting coffee beans aren’t the major problem to be wary of. The primary concern would be the mycotoxins present in the moulds. Coffee bean moulds can harbour a type of mycotoxin called “Ochratoxin A” (OTA). In high doses, OTA could prove toxic to the kidneys and overall carcinogenic. There could be health problems such as kidney damage, neurologic impairment, liver damage, and heart failure.

A common misconception about coffee made from mouldy coffee beans being very harmful. Realistically, the mould levels in a coffee drink can never be high enough to be detrimental. The healthy liver functions to detoxify the trace amounts daily. It might be safe even to say you should worry about caffeine overload before toxic doses of mould.

According to 2015 research, trace amounts of moulds in coffee are not harmful. Heavily exposed over a long time can lead to serious health issues. With mycotoxins and mildew, the dose makes the poison. People who drink large amounts of mouldy coffee or have mould sensitivities may suffer from the following signs.

  • Headaches
  • Anxiety
  • Dizziness and
  • Irritability

To better understand mycotoxins and their risks, check out what the WHO says about them.


How to Identify Mould on Coffee

For starters, the taste will be different. If you’ve been enjoying a vibrant taste of your early morning coffee initially, but suddenly the taste becomes musty, it might be due to mould. While moulds aren’t responsible for all taste changes, mouldy coffee beans brew will not have what fresh brew taste coffees should have.

If you prepare your coffee yourself, you can observe several things: the appearance, smell, taste and texture of your coffee beans. The coffee beans could develop a white fuzzy coating. Other times, moulds might not be detectable.

Another way to identify mouldy coffee is the side effects of drinking. You can notice the following side effects.

  • Fatigue
  • Headaches
  • Brain fog
  • Upset stomach
  • Respiratory problems. From coughing and sneezing to a runny nose.

In some cases, you might not experience any symptoms. As a result, using side effects as a criterion might not always be practical.


How to Deal With Mouldy Coffee

The best course of action when you encounter mouldy coffee beans or coffee altogether is to chuck them out or dispose of them. However, if you decide to save the beans, there are several things you could do on that note.

  • Rinse thoroughly mouldy coffee beans in cold water.
  • Use a blunted knife to cut persistent mouldy parts away
  • Get an airtight container. Full it up with 1 part vinegar and two parts water.
  • Pour your coffee beans into the container and cover. Allow the coffee beans to be immersed adequately into the solution.
  • Within 30 minutes, the vinegar peels the mould off the coffee beans.
  • Drain away the solution and then rinse the coffee beans in cold water.

This method isn’t foolproof but will help if you decide not to dispose of the beans. The coffee beans might also change their taste after being soaked in vinegar.


How to Avoid Coffee Mould

Some of the ways to avoid moulding in coffee include the following.

  • Patronise coffeehouses and coffee shops with great credibility and ratings.
  • Purchase better quality coffee beans.
  • Stay observant of cheap coffee types.
  • Invest in proper storage of your coffee beans or coffee grounds.
  • Clean your coffee-making equipment regularly and disinfect the presence of mouldy appearances.
  • Observe your coffee before brewing. Check the appearance, smell and texture.
  • Look for a certification from a respectable organisation or lab on the coffee product label.
  • Drink regular coffee. Unlike Decaffeinated coffee, regular coffee contains caffeine which is a mould deterrent.
  • Drink coffee made from beans cultivated at high altitudes only.

Coffee growers are aware of the potentiality of mouldy coffee beans. They make use of different methods to deal with this issue. The most crucial strategy is called “wet processing”.



Similar to most food, coffee beans can potentially get mouldy. Although the levels that could be present in your daily cup are nothing to worry about, it wouldn’t hurt to pay attention to details. If you’re still worried about drinking mouldy coffee, you could make some of the changes discussed or stop drinking coffee altogether. Hopefully, this article has enlightened you on the possible musty nature of your favourite beverage as well as how to deal with it.