Rendering

Rendering is a basic culinary technique whose essence lies in the slow heating of solid animal fat (most often pork fatback, as well as goose or duck fat) in order to release pure liquid fat from it.

Finely diced fat is slowly heated over low heat; the connective tissue contracts, and the pure fat gradually renders out, becoming clear. The solid remnants, meanwhile, brown and turn into crisp cracklings. The rendered and strained fat (for example, pork lard) sets into a soft mass and keeps for a long time. This technique yields two valuable products at once: a quality cooking fat for frying and baking, and a tasty garnish. Rendering is an example of a thrifty, zero-waste cuisine familiar to many peoples of the world.