Maize: Dry Milling

The maize dry milling process fractionates the maize kernel into the germ, pericarp, and endosperm components. The key processing step is proper tempering, which increases kernel moisture from 15 to about 22%, causes hydration of the germ, and allows proper separation of the germ and pericarp from the endosperm. Additional steps use physical properties to separate the endosperm, germ, and pericarp process streams. Modern dry milling produces grit (endosperm) products that have varying particles sizes with less than 1% fat, allowing long shelf life. The process also coproduces hominy feed, a mixture of the germ and pericarp, used in animal diets.