Quark (cheese) - Production

Production

Quark is a member of the acid set cheese group, meaning it is traditionally made without the aid of rennet. In most German dairies today, it is made with rennet. Lactic acid bacteria are added in the form of mesophilic Lactococcus starter cultures. Acidification continues until the pH reaches 4.6, which causes precipitation of the casein proteins. In Germany, the curd is continuously stirred to prevent it from getting hard, resulting in a thick, creamy texture. Quark is usually sold in plastic tubs with most or all of the whey. This type of quark has the firmness of sour cream but is slightly drier, resulting in a somewhat crumbly texture (like Italian ricotta), and contains in its basic form about 0.2% fat. Quark with higher fat content is made by adding cream, and is often sold flavored with herbs, spices, or fruit. It has a very smooth and creamy texture and is slightly sweet (unlike sour cream).

To make the firmer eastern European version, a small amount of rennet may be added to make the curd firmer. Some or most of the whey is removed to standardize the quark to the desired thickness. Traditionally, this is done by hanging the cheese in loosely woven cotton gauze called cheesecloth and letting the whey drip off, which gives quark its distinctive shape of a wedge with rounded edges. In industrial production, however, cheese is separated from whey in a centrifuge and later formed into blocks. The Polish, Lithuanian and Austrian varieties contain less whey and are therefore drier and more solid than varieties common in other countries.

Quark consists of 60% to 80% water. Dry mass has 1% to 40% fat; most of the rest is protein (80% of which is casein), calcium, and phosphate.