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Mold in Coffee – Are Mycotoxins in Coffee a Real Problem?

Mold in Coffee – Are Mycotoxins in Coffee a Real Problem?

Have you ever heard people warning you about mold in certain coffees, and wondered if it’s a real concern?

You’re not alone – mold in coffee is a well-known issue that’s been discussed and dealt with for years in the coffee industry. But why does mold sometimes form in some coffees, and how can you be sure you’re drinking mold-free coffee?

We’ve got you covered – today, you’re in for a deep dive on all the frequently asked questions about mold in coffee, and 8 solid ways to ensure you’re drinking mold-free coffee.

Mold vs Mycotoxins: What’s the Difference?

Molds and mycotoxins are often used interchangeably when speaking about mold in coffee, but they’re not exactly the same thing. 

Two cups of mold-free coffee on wooden table.

Molds are tiny spores that grow on foods and other organic materials in hot and humid conditions. As you probably know, mold is typically a sign that food’s gone bad and should be avoided, since large amounts of mold can make you sick. 

Mycotoxins are toxic chemicals formed by molds. While some of them make you sick or could potentially cause chronic health issues, other mycotoxins are used in medicine such as penicillin and certain anti-migraine drugs

The two mycotoxins that are most common in coffee are called Aflatoxin B1 and Ochratoxin A. Aflatoxin B1 is a known carcinogen and can cause various other health issues. Ochratoxin A, on the other hand, is less researched but also believed to be a mild carcinogen that could potentially cause kidney damage

When we talk about mold in coffee, the mycotoxin levels are what we’re mostly concerned about, and coffee can contain traces of them even if your coffee doesn’t look moldy. 

What Causes Mold in Coffee?

There are multiple different ways for mold to form in coffee. Let’s take a look at the most common ones, shall we? 

Coffee’s Growing Conditions

Mold in coffee can begin as early as the crop. The coffee plant grows in hot and humid areas, such as rainforests and the slopes of Peru, Guatemala, and Brazil. These conditions are ideal for mold to form, and the coffee plant is not immune. When the coffee cherries are harvested, small mold spores may have already formed. 

Freshly picked, shade-grown coffee cherries.

Processing of Coffee Beans

When the coffee cherries are harvested, their outer layers (the mucilage) are stripped to get to the coffee bean inside. There are different ways to do this, and the most common methods are called dry-processing and wet-processing

Coffee beans transported in burlap sacks.

With dry processing, the coffee cherry is left to dry naturally in the sun, and then the dried fruit is stripped off the bean. Because the bean is left wrapped in the moist mucilage for longer, this process tends to lead to the most mold

Wet processing instead strips the beans of the mucilage straight away using water. But it’s important that the beans are dried properly afterward, or they become the ideal growing bed for mold, too. 

Shipping Conditions May Cause Mold

Studies have found that green coffee beans (meaning, beans that have yet to be roasted) are much more susceptible to mold – in fact, roasting coffee beans can reduce mold levels by 42-55%.

But often, green coffee beans are shipped for weeks before reaching the roasters, and during this time, mold may also form. Especially with beans that are shipped in burlap sacks, since they don’t protect very well from humidity. 

Is Mold in Coffee Dangerous?

As we’ve already established, the mycotoxins most commonly found in coffee may be harmful. But the levels found in coffee, even low-quality blends with higher levels of mold than average, are typically far below the levels deemed dangerous for humans

Rich, mold-free coffee pouring into mug.

In other words, it’s very rare for mold in coffee to cause real health issues for humans, even if you do drink coffee on a regular basis. Because your liver can take care of mycotoxins, there’s no buildup happening in your body, and unless you’re exposed to much higher levels of mycotoxins than present in your morning cup of coffee, you don’t have to worry.

According to board-certified physician Dr. Cederquist, “Something like four double espressos per day would be considered high-level exposure and may increase the risk.” But if you keep within the daily recommended amount of coffee consumption (about 4-5 regular-sized cups per day), there’s no real cause for concern about mycotoxins.

Besides, coffee is far from the only food or beverage that contains small traces of mold – you’re exposed to various types of mycotoxins from an array of things, and avoiding it completely is virtually impossible. 

That said, you might still want to minimize the levels of mycotoxins and mold in the coffee that you drink – the less, the better, right?

8 Ways to Prevent Mold in Coffee

As you can tell, mold in coffee often begins long before you buy it at the shops, but that doesn’t mean you can’t pick coffees with less chance of mold in them. Here are a few factors to consider in your pursuit of mold-free coffee


1. Growing Conditions

Mold is less likely to grow at high altitudes, which is good news for coffee lovers – some of the best-flavored beans, and the Arabica variety especially, grow best at high altitudes, too. So, look for beans that have grown at high altitudes to minimize any chance of mycotoxins in your cup.


2. Type of Bean

If you’re worried about mycotoxins in your cup, always opt for Arabica beans over Robusta blends. Robusta beans are more susceptible to mycotoxins, so this simple choice could make a big difference. 

Roasted, mold-free coffee beans.

3. Roast Level

Studies comparing the levels of mold in a variety of different roasts found that generally, darker roasts contain less mold. This is because the heat of the roasting process reduces the mold levels in the coffee beans. 

Naturally, this means that so-called green coffees, which are made from unroasted beans, have a higher risk of containing mycotoxins than roasted coffee, while darker roasts are generally safer. 

4. Brewing Method

Similar to the roasting process, the brewing method you choose may also help to reduce any residue of mold. Since humidity and heat increase the chances of mold, you want to choose a method where the hot water is only in contact with the grounds for a short time. 

Moka pot brewing in nature.

A recent study found that coffee made with Moka Pots reduced the mycotoxins in the final brew by between 50-75%, while longer infusion methods like Turkish coffee making (about 10 minutes of infusion), had little, if any, reduction of mold particles. Likewise, instant coffee contains more mycotoxins than regular coffee. 


5. Caffeine Helps Prevent Mold

Caffeine actually helps to prevent the growth of mold, so coffee with high levels of caffeine is less likely to contain mycotoxins. Likewise, decaf blends tend to be higher in mycotoxins for the same reason. However, if you’re a decaf drinker, don’t worry – levels are still far below harmful so long as you don’t consume coffee excessively. 


6. Pick Roasters That Test for Mold

Not all roasters test for mold and mycotoxins, but those that do are, quite naturally, a better choice. This way, you can sip coffee knowing that regardless of the production route your coffee has taken, the final beans in your bag are not harmful to you. 

Not sure how to find out whether a roaster tests for mold and mycotoxins? Since not all brands that test their coffee post their test results, it can be difficult to know whether a brand does or doesn’t test for mycotoxins. 

Cup of coffee with latte art.

If you’re worried, though, you can always reach out to the coffee company itself and ask them whether they do check for mold and mycotoxins. If they do, they should have no issues filling you in on the details. The testing should be done by an independent, third-party lab, and they should be able to tell you which company did the test, when, with what method, and what the results were. 


7. Choose Highest-Quality Specialty Coffee 

Not only do high-quality coffee brands work with better-quality beans. They typically take more care to ensure that the entire production, from crop to cup, is ethical, safe, and controlled. If you’re looking for coffee that has been tested for mold and mycotoxins, picking a high-quality coffee brand is a pretty safe bet. 

In fact, the quality of coffee is rated on a grading system, and coffee with high levels of mold falls significantly on the scale. So, found yourself a high-quality coffee you like? You likely shouldn’t have to worry too much about mycotoxins. 


8. Store Your Coffee Properly

Finally, coffee can grow mold even after you’ve taken it home from the store. So, once you’ve opened your coffee’s packaging, make sure to store the beans in air-tight containers, and ideally in a cool and dry place. 

Mold-free Coffee – Try Peak State’s Organic Blends

Looking for mold-free coffee? Check out Peak State’s range of delicious roasts for a cup that’ll take you to new heights. 

As a health-conscious coffee brand, all of our roasts are carefully tested by a third-party lab to ensure they are mold and mycotoxin free, and that your brew is as good for you as possible. We only use shade-grown arabica beans from high-altitude farmers, and our coffee is both organic and Fair Trade certified. 

Peak State top-seller coffee starting pack.

To give you an extra health boost, we also infuse our beans with antioxidant-rich functional ingredients, such as reishi, lion’s mane, and cordyceps. New to mushroom coffee? Learn all the health benefits here

Curious to give it a try? Pick a roast and have your free sample delivered right to your front door today! 

Bottomline: Is Mold In Coffee Dangerous?

Due to the growing conditions and processing methods of coffee beans, some coffees contain traces of mycotoxins and mold. But coffee is far from the only food and beverage that does, and luckily, the levels of mold in coffee are far below dangerous so long as you consume a normal amount. 

That said, picking coffee with fewer mycotoxins is healthier for you in the long run. Some easy ways to find mold-free coffee include picking arabica beans over robusta, choosing darker roasts with high caffeine levels, and buying from brands that test the levels of mold in their roasts. How you brew your coffee could also make a difference in your morning cup of joe. 

Psst… Is coffee giving you heartburn? Check out these 6 proven ways to avoid it

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