Quark is a type of fresh dairy product made by warming soured milk until the desired degree of curdling is met, and then straining it. It can be classified as fresh acid-set cheese, though in some countries it is traditionally considered a distinct fermented milk product. Traditional quark is made without rennet, but in some modern dairies rennet is added. It is soft, white and unaged, and usually has no salt added.
It is common in the cuisines of German-speaking countries (Germany, Austria, Switzerland), northern Europe (Denmark, Estonia, Finland, Iceland, Latvia, Lithuania, Norway, Sweden), the Netherlands,Hungary, Belgium, Albania, Israel, Romania, of Slavic peoples (e.g. Czechs, Slovaks, Poles, Russians, Ukrainians and Belarusians, Slovenes, Croats, Macedonians, Bulgarians, and Serbs), and of Ashkenazi Jews. It is also somewhat common in Canada as well as northeastern and midwestern United States.