Quark or quarg (sometimes translated as curd cheese) is a type of fresh dairy product made from milk. The milk is soured, usually by adding lactic acid bacteria cultures, and strained once the desired curdling is achieved. It can be classified as fresh acid-set cheese. Traditional quark can be made without rennet, but in modern dairies small quantities of rennet are typically added. It is soft, white and unaged, and usually has no salt added.
Quark and its dryer variant tvorog are traditional in the cuisines of Baltic, Germanic and Slavic-speaking countries as well as amongst French, Romanians, Italians, Hungarians, Greeks, Ashkenazi Jews and various Turkic peoples. Quark is similar to other fresh cheeses including the French fromage blanc, cottage cheese, and farmer cheese.