Temperature, pH, water hardness and antimicrobials are all important factors in effective water chilling of poultry carcasses. The USDA-FSIS requires broiler carcasses to be chilled to less than 4 C within 4 hours of slaughter. In order to meet this requirement most plants in the USA immersion chill carcasses. Technically speaking, this process is the first step in the cold chain for poultry meat processing and is a very important food safety intervention.