Shredded cabbage that has been mixed with a brine of pickling salt and spices after which it is allowed to ferment for a period of time. The fermented cabbage develops a pungent or sour flavor that is cooked to enhance the flavor of casseroles and side dishes, or served raw on sandwiches, hot dogs and brats. When preparing sauerkraut, wash the shredded bits to remove excess brine and salt. It is available in jars or cans, and fresh sauerkraut can often be found in the refrigerated section of stores.