Sour milk cheese or fermented milk cheese is a type of cheese that is made from milk that has begun to sour or ferment. This type of cheese is known for its tangy, slightly acidic flavor and crumbly texture. Some common synonyms for sour milk cheese include cultured cheese, acid cheese, and acid-curd cheese. Other variations of sour milk cheese include quark cheese, cottage cheese, and kefir cheese. Despite its pungent flavor, sour milk cheese is still a popular food item, particularly in Scandinavian, Eastern European, and Russian cuisines. It is often used in dips, spreads, and as a topping for bread and crackers.