Chilling, Food Safety Glossary

Cooling food to refrigeration temperature and keeping it at or below 5 degrees C to slow bacterial growth. Chilling means bringing food down to refrigeration temperature and holding it cold, at or below 5 degrees C, so that food-poisoning bacteria grow only very slowly. Keeping cold food below 5 degrees C keeps it out of the part of the temperature danger zone where bacteria multiply fastest, which is central to keeping potentially hazardous food safe under the Australia New Zealand Food Standards Code. Chilling covers both cooling food down after cooking and holding food cold during storage and display. When hot food is being chilled, the aim is to move it through the danger zone quickly, following the two-stage cooling guide of 60 degrees C to 21 degrees C within two hours and then 21 degrees C to 5 degrees C within a further four hours. Once chilled, food must be kept at or below 5 degrees C throughout storage, display and transport. In Australian kitchens, chilling shows up as cooling cooked food promptly, storing cold food at or below 5 degrees C, and displaying cold items such as salads and sandwiches in refrigerated units. Staff use shallow containers or a blast chiller to speed cooling, and a probe thermometer to confirm the core temperature has reached 5 degrees C before food is stacked or covered in the cold room. Holding food cold is only reliable if fridges are working and not overloaded, so temperature monitoring of chilled storage is routine. Where cold food has to leave refrigeration, for example on a display or during transport, businesses track the time using the 2-hour / 4-hour rule for ready-to-eat potentially hazardous food. A deli cooks a batch of roast beef, then chills it by slicing it into a shallow tray and placing it in the cold room, checking that the core reaches 5 degrees C within the cooling time limits. The sliced beef is then held in the chilled display at or below 5 degrees C, with the display temperature checked during service.