The birds go through several steps before being cut and packaged.
Precise steps in poultry processing prevent contamination and produce a bird that is not tough or marred with skin blemishes. The birds go through stunning, slaughtering, bleeding and scalding processes before the sebaceous glands, feet and head are removed. After the birds are washed, they are rapidly cooled before being cut up, aged, and packaged for distribution.
Chicken feathers are removed by placing the dead bird in a rotating drum equipped with rubber fingers that abrade the feathers.
Birds are typically packaged and transported to poultry processing plants, where they are kept in misted and ventilated holding areas. A special blue light is sometimes used to keep birds calm while they are hung on racks for the stunning step, because wing flapping can cause internal bleeding that discolors the meat. Birds are often submerged in salt water with an electrical current that renders them unconscious for a minute or two. Radon gas is used in some regions to stun birds, but is considered more expensive.
The brief period that a bird is unconscious gives the processing plant enough time to kill it and allow it to bleed. Draining the blood prevents the meat from looking dark. In large poultry processing facilities, blood is treated as a waste and contaminant.
The birds then move to scorching pools, where the hot water loosens the feathers for harvest. It is important to keep the water temperature regulated to prevent the bird from overcooking. The water should also be changed frequently to prevent contamination. After scalding, the bird is kept moist so that the skin does not begin to darken.
Plucking, or harvesting, is commonly done by machines in large processing plants. Birds are placed in rotating drums equipped with rubber fingers that abrade their feathers. The remaining feathers can be waxed for easy removal. In some poultry processing operations, fine feathers are singed.
The next step involves evisceration, the removal of the bird’s head, feet, and oil glands located at the top of the tail. The machines often rip off the head, while the feet are cut off at the knee joint. Birds use the sebaceous gland to straighten their feathers, but it contains a bad smell and taste. Food safety regulations generally require that the viscera be with the bird during this part of the process so that an inspector can examine the interior and exterior for disease. A torn intestine can contaminate the meat, but some countries allow a chlorine wash to solve the problem.
The bird carcasses are then washed and rapidly cooled in cold water or by blasting cold air directly into the bird’s cavity. Poultry chilling is most common in Europe and Canada, but represents a typical process for lamb, pork and beef internationally. The bird is now ready to be cut into pieces and deboned. Poultry processing can include chopping, pressing, and breading the meat to make chicken nuggets, deli meats, or hot dogs.
Aging requires a minimum of four hours to keep the meat tender before the birds are frozen or eaten. The final step in poultry processing involves weighing, labeling, and packaging. It is now ready for distribution in supermarkets for purchase by consumers.