Dünnung in German butchery refers to a set of cuts from the lower belly and flank area of the cow. These are parts of the animal that are regularly exercised and, as a result, contain well-developed muscles with a substantial amount of connective tissue.
Due to its location on the cow and the constant movement in this area, dünnung has a pronounced muscle structure, making it somewhat tough in texture. However, this exercise also imparts a deep, beefy flavor to the meat, making it highly desirable for certain preparations.
Due to its inherent toughness, dünnung benefits from a prolonged cooking time at a low temperature. This allows the collagen and connective tissues to melt into the dish, rendering the meat tender and adding richness to the cooking liquid. A preliminary step of browning the meat can enhance the depth of flavor in the final dish.