Yeast and mold are organisms of great importance to the food industry. These two species are very different from bacteria, which are more commonly associated with food borne illness. Hundreds of yeast and mold species have been isolated from foods and due to their ability to grow over a wide spectrum of environmental conditions very few foods are entirely safe from fungal spoilage.
At some point in our lives, all of us have observed some sort of mold spoilage – be it on piece of bread or on a peach you left sitting on your kitchen counter for an extended period of time. While not as easily visible, yeast are also troublesome organisms worthy of our attention. The following section describes key yeast and mold characteristics, features that differentiate them from bacteria, and important considerations to help prevent potential contamination associated with these species.