Propionic acid fermentation by Propionibacterium freudenreichii is the fermentation of lactic acid and it influences the sensory characteristics of cheese in various ways. In addition to the usually pronounced eye formation, cheeses with propionic acid fermentation are especially characterized by a distinctive sweet taste. This article takes a comprehensive look at the different types of semi-hard and hard cheeses with propionic acid fermentation, with a detailed focus on specific aspects such as technology, cultures, ripening patterns, eye formation, textural characteristics, flavor characteristics, and nutritional aspects, as well as undesired cheese defects and hygienic safety.