Best Method to Chill Chickens Depends on Water
Durham April 14, 2008
Chilling is an important step in processing poultry carcasses
before marketing of the birds, and there are different ways to do it.
Agricultural Research Service (ARS)
scientists at the
B. Russell Research Center in Athens, Ga., recently compared two chilling
methods to determine which better suits processors' needs.
Food technologist Julie Northcutt, formerly with the ARS Poultry
Processing and Swine Physiology Research Unit at Athens, and food technologist
Smith, in the
Quality and Safety Assessment Research Unit at Athens, evaluated the two
primary industry methods in terms of meat quality, food safety and water
Carcass temperatures must be quickly lowered after poultry slaughter
to prevent growth of bacterial pathogens that may cause food-borne illness when
consumed. Immersion chilling--in which chicken carcasses are submerged in tanks
of cold water or an ice-and-water mix--is the predominant method now used in
the United States. Dry-air chilling blasts carcasses with cold air, while
evaporative-air chilling combines cold air blasts with water misting. Some
poultry processors are beginning to convert to dry-air chilling.
Both immersion chilling and air chilling met criteria for limiting
bacterial pathogen growth on carcasses. But tender chicken is also very
important to consumers. During commercial processing, whole carcasses are aged
under refrigerated conditions to allow muscle fibers to relax and become
tender. Research showed that air chilling led to better quality of breast
fillets and provided higher cooked-meat yields than immersion chilling.
In the end, water may be the most important factor in deciding which
chilling method may be most feasible in the future. It takes an average of
seven gallons of water to process each chicken, and switching to air chilling
can save a minimum of one-half gallon per bird. Processors could save about 4.5
billion gallons of water per year if all 9 billion birds processed annually in
the United States were air-chilled.
more about the research in the April 2008 issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.