Rendering

Rendering is a process that converts waste animal tissue into stable, value-added materials. Rendering can refer to any processing of animal products into more useful materials, or more narrowly to the rendering of whole animal fatty tissue into purified fats like lard or tallow.

History

Rendering was a historically important but often forgotten part of animal husbandry. Those parts of a carcass that are not directly edible or marketable as meat are instead processed, generally by heating, to produce a variety of materials that are broadly categorized as "by-products". These include tallow, lard, gelatin, glue, fertilizer, and animal feed.

Process

The rendering process simultaneously dries the material and separates the fat from the bone and protein. A rendering process yields a fat commodity (yellow grease, choice white grease, bleachable fancy tallow, etc.) and a protein meal (meat and bone meal, poultry byproduct meal, etc.).

Health and safety

Rendering plants often also handle other materials, such as slaughterhouse blood, feathers and hair, but do so using processes distinct from true rendering.

Environmental impact

The rendering industry is a significant part of the agribusiness chain. It is instrumental in the conversion of waste animal tissue into useful materials.

See also

• Animal by-product
• Biodiesel
• Biofuel
• Blood meal
• Bone meal
• Meat and bone meal
• Tallow
• Yellow grease