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

Every so often, we get questions about mold and mycotoxins in coffee. You may have seen headlines or ads claiming coffee is a major source of mold exposure, or that certain brands are somehow “mold-free” while others are not. It’s an understandable concern, and one that deserves a clear, level-headed explanation.

Rather than leaning on marketing claims, we find it’s more helpful to talk about how coffee is grown, processed, stored, and roasted, and why those steps matter so much.

What Are Mycotoxins?

Mycotoxins are naturally occurring compounds produced by certain molds. They can show up in a wide range of agricultural products, including grains, nuts, dried fruit, and in some cases, coffee. The two most commonly discussed in relation to coffee are ochratoxin A (OTA) and aflatoxins.

At very high levels and over long periods of exposure, certain mycotoxins have been linked to health concerns. Because of this, regulatory agencies like the FDA and the European Food Safety Authority set strict limits on allowable levels in food and beverages, including coffee.

The important context is that coffee sold through commercial channels, especially specialty coffee, is almost always far below those limits. When coffee is processed, stored, and roasted correctly, mycotoxin levels are typically negligible.

Why Mold Can Develop in Coffee

Coffee is an agricultural product, and like most dried crops, moisture management is a big focus in quality control. Mold thrives in warm, humid environments where moisture content is higher than it should be.

If coffee is not dried thoroughly after harvest, or if it is later stored in damp or unstable conditions, mold can develop. Even properly dried green coffee can reabsorb moisture if it is exposed to high humidity during storage or transport.

This is where quality practices make a real difference. Specialty coffee producers are meticulous about drying coffee to an optimal moisture range, usually between 10 to 12 percent. From there, the coffee is stored and shipped in protective liners such as GrainPro or Ecotact, often within climate-controlled warehouses. These steps help preserve flavor and stability while minimizing the risk of mold growth.

Lower-quality commodity coffee, which is traded at much lower prices, is more likely to be dried quickly, stored in bulk, and shipped without these added protections. That difference in care is one of the many reasons specialty coffee tastes better and holds up better over time.

Should You Be Concerned About Mycotoxins in Coffee?

For most people drinking well-sourced specialty coffee, this is not something that needs to be a daily worry. A few key reasons 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 – International guidelines for safe storage of agricultural products identify low moisture levels as critical. Specialty coffee standards fall well below those thresholds, balancing flavor development with long-term 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?

You may see some brands market their coffee as “mold-free” or heavily emphasize mycotoxin testing. While testing can be done, these claims are often more about marketing than a meaningful difference in safety.

Well-sourced specialty coffee already follows best practices that minimize these risks naturally. When care is taken at origin and throughout the supply chain, there is rarely a need for dramatic labeling or premium-priced reassurance.

Our Approach to Quality & Safety

Here at the roastery, we take quality and safety seriously. We don't pretend to be health experts, nor to wish to make claims for the sake of marketing, but 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 roaster you trust, mycotoxins are not something you need to stress about. Coffee that is grown, handled, and roasted with care is not only safer, it also tastes better.

Good coffee starts with good practices. When those are in place, you can focus on what really matters: enjoying the cup in front of you.