Mold, Mycotoxins, and Coffee: What You Need to Know

At FreeForm, we believe in transparency and sharing what we’ve learned over years of sourcing, roasting, and brewing coffee. One topic that occasionally comes up is mold and mycotoxins. You may have seen claims that coffee is a major source of mold exposure or that some brands offer ‘mold-free’ alternatives. Let’s break down the facts and how specialty coffee—when sourced and processed with care—naturally minimizes these concerns.

What Are Mycotoxins?

Mycotoxins are naturally occurring compounds produced by certain molds. They can be found in various agricultural products, including grains, nuts, dried fruit, and, in some cases, coffee. The most commonly discussed mycotoxins in coffee are ochratoxin A (OTA) and aflatoxins, which have been studied for their potential health effects.

While low levels of mycotoxins are generally considered harmless, long-term exposure to high levels of certain mycotoxins—such as ochratoxin A—has been linked to potential health risks, including kidney damage and immune system suppression. This is why regulatory bodies like the FDA and the European Food Safety Authority (EFSA) set strict limits on allowable levels in food and beverages, including coffee. Fortunately, specialty coffee, when properly processed and stored, rarely contains mycotoxin levels anywhere near these regulatory limits.

Why Does Mold Grow in Coffee?

As we know, mold thrives in warm, humid environments with excess moisture—conditions that can occur when coffee is improperly dried and/or stored. Coffee is a dried agricultural product, and if the drying process is not carefully managed, lingering moisture can create the perfect conditions for mold growth. 

Even after proper drying, storage conditions play a crucial role. If green (unroasted) coffee is exposed to high humidity or fluctuating temperatures, it can reabsorb moisture, leading to potential mold development. 

Specialty coffee producers take great care to ensure that coffee is dried to an optimal moisture level (typically 10-12%) before storage to prevent this issue. Commodity coffee, which is often bulk-stored in less controlled environments, may be more susceptible to these conditions. In contrast, specialty coffee is typically stored in breathable, protective bags (such as GrainPro or Ecotact liners) within climate-controlled warehouses to preserve quality and prevent mold growth.

By sourcing high-quality coffee from producers who follow strict drying and storage practices, we ensure that the coffee we roast and serve is free from these risks—allowing you to enjoy a clean, flavorful cup.

Should You Be Concerned About Mycotoxins in Coffee?

For those buying high-quality specialty coffee, mycotoxins are not a major concern. Here’s why:

1. Specialty vs. Commodity Coffee – Not all coffee is created equal. Traded at lower prices, lower-quality commodity coffee may be more susceptible to low-quality processing and improper drying and storage—the biggest culprits for mold development in coffee. In contrast, high-quality specialty coffee is traded at much higher prices, justifying the expenses required for careful quality control at every step of harvest and processing. 

2. Controlled Moisture Content – The Food and Agriculture Organization of the United Nations identifies a moisture level of 13.5% and lower for safe grain storage. Specialty coffee standards identify an acceptable range of 10-12% moisture content for an optimal balance of flavor and stability.

3. Hermetically Sealed Storage – Specialty coffee is stored and transported in gas-tight and moisture-tight bags such as GrainiPro or Ecotact liners within jute sacks, often within climate-controlled warehouses.  Commodity coffee prices don’t justify these added expenses and is typically stored and shipped in breathable and penetrable jute sacks alone.  

4. Scientific Studies & Regulations – Multiple studies have shown that mycotoxin levels in commercially available coffee are typically well below safety thresholds set by organizations like the FDA and the European Food Safety Authority. Many mycotoxins also break down during the roasting process, further reducing any potential risk.

What About “Mold-Free” Coffee Claims?

Some brands market their coffee as “mold-free” or “tested for mycotoxins,” often at a premium price. While mycotoxin testing can be done, ‘mold-free’ claims are often more about marketing than meaningful differences in safety. Specialty coffee roasters already follow best practices that make such branding largely unnecessary. Specialty coffee roasters like us prioritize sourcing from farms that already follow best practices, making additional “mold-free” branding largely unnecessary.

Our Approach to Quality & Safety

Here at the roastery, we take quality and safety seriously. While we don’t make exaggerated claims, we do ensure that our coffees:

• Are sourced from producers who follow strict drying and storage practices
• Are verified for proper moisture content once they arrive at our roastery
• Are stored in hermetically-sealed bags in our clean, climate controlled warehouse until roasted
• Are sourced transparently and held to high-quality standards at every step of the supply chain.
  

The Bottom Line

If you’re drinking high-quality specialty coffee from a trusted roaster, mycotoxins are not something you need to worry about. The real takeaway? Choose well-sourced, well-roasted coffee, and you’ll enjoy a better cup—both in terms of flavor and quality.