Why does blue cheese have yeast in it?

Blue cheese contains specific strains of mold, particularly Penicillium roqueforti, which is responsible for its characteristic flavor and blue veins. The presence of yeast is important for the fermentation process, contributing to the development of the cheese's unique taste and texture. Yeast helps in the breakdown of fats and proteins, enhancing the overall complexity of flavors in the cheese. Additionally, it aids in the aging process, allowing the cheese to develop its distinct aroma and taste profile.