Quark is a form of Central European soft cheese which is especially popular in Germany, where a number of dairies produce it. It is possible to find quark in other regions of the world, although it may take a bit of hunting, depending on where you live. When you do find it, it may be a bit expensive, as this cheese is a bit fragile, requiring careful handling along the way to market. Quark cheese can also be made at home, if you are comfortable with the cheesemaking process; this cheese is relatively easy to make.
Quark is a fresh cheese, traditionally made with unpasteurized milk, although versions available in stores may be made with pasteurized milk, out of concern for consumer safety. In any case, the cheese only keeps for around a week, requiring people to use it quickly. Fortunately, quark is incredibly versatile, being useful in everything from dips to cheesecakes. This cheese has a mild, slightly tangy flavor which pairs well with a variety of foods.
Traditional quark cheese is pale cream to white in color, very thick, and creamy. Some people mistake quark for cream cheese, a similar product, but quark is a bit thinner than cream cheese, and it is made in a different way. Quark can be spread on bread plain, blended with herbs and spices to make a flavored spread, or it may be used like cream cheese in cheesecakes. It can also be offered as a dessert cheese or made into a rich cheese custard which can be served with fruit or other foods.
Classically, quark is made without rennet, which means that this cheese is safe for vegetarians and observant Jews to eat. It is made by heating milk, mixing it with a culture, and then stirring the milk as it curdles. The stirring keeps the quark cheese creamy, ensuring that it will be smooth, rather than grainy. Once the cheese has thickened, it is hung in a cheesecloth bag to allow the whey to drain off, and then it is typically packed into a small clay or glass pot for storage.
In some parts of Europe, rennet may be added to quark to thicken this cheese, catering to the tastes of people who want a denser cheese. If the consumption of rennet is a concern for you, look for quark cheese which is labeled as kosher or pareve, indicating that it has been certified by a rabbi as safe to eat for observant Jews. Because Jewish dietary law forbids the consumption of meat and milk together, a kosher cheese cannot contain rennet.