Precise steps in poultry processing prevent contamination and produce a bird that is not tough or marred with skin blemishes. Poultry goes through stunning, killing, bleeding, and scalding processes before oil glands, feet, and head are removed. After the birds are washed, they are quickly chilled before being cut up, aged, and packaged for distribution.
Birds are usually crated and transported to poultry processing plants, where they are kept in holding areas that are ventilated and misted. A special blue light is sometimes used to keep the birds calm once they are hung on racks for the stunning step, because flapping wings can cause internal bleeding that discolors the meat. The birds are commonly dipped into saline water with an electrical current that renders them unconscious for a minute or two. Radon gas is used in some regions to stun poultry, but it is considered more expensive.
The brief period a bird remains unconscious gives the processing plant enough time to kill it and allow it to bleed out. Draining the blood prevents the meat from appearing dark. In large poultry processing facilities, the blood is treated as a waste product and pollutant.
Birds then move to scalding tanks, where hot water loosens feathers for picking. It is important to keep water temperate regulated to prevent cooking the bird. Water must also be changed frequently to avoid contamination. After scalding, the poultry is kept moist so the skin does not begin to darken.
Plucking, or picking, is commonly done by machine in large processing plants. The birds are placed into rotating drums outfitted with rubber-like fingers that remove feathers through abrasion. Any remaining pinfeathers can be waxed to make removal easier. In some poultry processing operations, the fine pinfeathers are singed.
The next step involves gutting, removing the head, feet, and oil glands located at the top of the bird’s tail. Machines commonly pull the head off, while the feet are severed at the knee joint. Birds use the oil gland to preen their feathers, but it contains a bad odor and taste. Food safety regulations commonly require that the guts stay beside the bird during this part of the process so an inspector can examine the inside and outside for disease. A torn gut can contaminate the meat, but some countries allow a chlorine wash to address the issue.
Poultry carcasses are then washed and quickly chilled in cold water or by blasts of cold air directly into the bird’s cavity. Air chilling of poultry is more common in Europe and Canada, but it represents a typical process for lamb, pork, and beef internationally. The bird is now ready to be cut into parts and deboned. Poultry processing may include chopping, pressing, and breading the meat for chicken nuggets, luncheon meats, or hot dogs.
Aging requires a minimum of four hours to keep the meat tender before poultry is frozen or consumed. The final step of poultry processing involves weighing, labeling, and wrapping. It is now ready for distribution to grocery stores for purchase by consumers.