Propionic cheese culture is a group of beneficial bacteria used to ripen Swiss-style cheeses, especially Emmental. It produces a mild, sweet, nutty flavor and carbon dioxide that forms the cheese’s characteristic holes, while contributing to a firm yet supple texture. Cheesemakers add it during production, and the resulting cheeses are enjoyed worldwide in dishes such as fondue, sandwiches, and gratins. Its use is closely associated with the long tradition of Swiss Alpine cheesemaking.