hulling

Hulling is the process of removing the hull, husk, or outer shell from seeds, grains, or other plant materials. The hull is a protective layer that surrounds the edible kernel in many cereals and seeds. Hulling is performed to improve edibility, texture, digestibility, milling efficiency, and storage properties, and to prepare the grain for cooking or further processing.

The hulling process is typically mechanical. Equipment such as decorticators, dehullers, or abrasive rollers physically separate the hull from the kernel through friction, impact, and controlled moisture. The exact method depends on the crop, the strength of the hull, and the desired degree of removal. Proper control of moisture content and handling is important to minimize kernel damage and reduce loss of edible material.

Common crops processed by hulling include rice, barley, oats, sorghum, and millet. In rice production, hulling removes the husk to produce brown rice, which can then be polished to white rice through additional milling. In barley and oats, hulling removes the husk to yield edible kernels; some processing sequences further pearling or polishing to reduce bran layers for refined products. In crops with naturally loose hulls, hulling may be simpler, while others require more intensive treatment to separate firmly attached hulls.

By-products of hulling, such as hulls or husks, are often used as animal feed, fiber sources, or as raw material for industrial uses. Hulling thus influences milling yields, nutritional composition, cooking properties, and environmental aspects of grain processing.