We check each container of coffee that we receive for moisture content and water activity (in addition to other quality evaluations). Molds can develop at ~15% moisture and above. Water activity refers to unbound water found in coffee which is not bound to coffee molecules and which is free to support the growth of bacteria, yeasts and molds/fungi. Coffees received which are outside of our quality specifications for moisture or water activity are tested specifically for mycotoxin contamination. We store the coffee in a temperature controlled environment until right before roasting at 450-550 degrees Fahrenheit.
All of these testing and handling processes limit any opportunity for mold/fungus growth.
More Here: Mycotoxins