Tallow is a rendered form of beef or mutton fat, primarily made up of triglycerides. In industry, tallow is not strictly defined as beef or mutton fat. In this context, tallow is animal fat that conforms to certain technical criteria, including its melting point. Commercial tallow commonly contains fat derived from other animals, such as lard from pigs, or even from plant sources. The adjacent diagram shows the chemical structure of a typical triglyceride molecule.