The development of a hot water treatment to reduce bacterial numbers on poultry carcasses is described. Initial trials identified suitable time/temperature for hot water immersion treatments and in subsequent work an experimental in-line processing unit was constructed and evaluated. Microbiological testing for organisms that are indicators for potential food spoilage (aerobic plate count) and human disease (Enterobacteriaceae, Campylobacter) was performed to assess the benefit of the treatment. A treatment of 75degreesC for 30 s significantly reduced the numbers of bacteria but the chicken skin tended to tear as the legs and wings were moved into position for a neat pack appearance (trussing). A treatment of 70degreesC for 40 s, however, did not detrimentally affect the chicken skin. In addition, aerobic plate, Enterobacteriaceae and Campylobacter counts for treated samples were significantly lower than the controls (P = 0.005) for 8 days under typical chilled storage conditions. (C) 2003 Elsevier Ltd. All rights reserved.