Penicillium is a genus of mold fungi used to ripen certain cheeses and cure some dry-cured meats. In cheesemaking, specific species are introduced to curds or applied to the rind; as the mold grows it breaks down proteins and fats, producing the veining, rind, and pungent flavors typical of blue and soft-ripened cheeses. Penicillium roqueforti creates the blue-green veining in cheeses like Roquefort, Gorgonzola, and Stilton, while Penicillium camemberti forms the white bloomy rind on Brie and Camembert. The same genus also includes Penicillium notatum, the source of the antibiotic penicillin, but that species plays no role in food production. Because it is a mold, Penicillium-ripened products should be handled and stored properly, and people with mold sensitivities may need to avoid them.