Thawing frozen food

Thawing frozen potentially hazardous food may pose a food safety riskFood Safety Supervisors understand that thawing frozen potentially hazardous food may pose a food safety risk if the temperature of the food is between 5°C and 60°C during thawing, allowing food poisoning bacteria to grow.

The food safety risk is much higher for frozen ready-to-eat potentially hazardous food being thawed than for frozen raw potentially hazardous foods that will be cooked or otherwise processed to make them safe before eating.

Ready-to-eat frozen potentially hazardous foods should be thawed in a refrigerator operating at 5°C or below, or alternatively in the microwave. If these foods are thawed at room temperature, food poisoning bacteria may grow in the food and as the food will not undergo any further processing (such as cooking) before it is eaten, the bacteria will not be destroyed. It is important that, if the food is thawed at room temperature the time that the food is at temperatures between 5°C and 60°C needs to be noted to ensure that safe time limits are not exceeded.

Hazards of thawing frozen food

  • thawing potentially hazardous food out of refrigeration can allow bacteria to multiply (i.e. under running water or on the bench at room temperature);
  • bacteria in juices from raw or thawing potentially hazardous food can drip onto ready-to-eat food, and contaminate it. This is one example of cross contamination;
  • the centre of partially thawed potentially hazardous food may be frozen and may not cook properly, allowing bacteria to survive;
  • food may become contaminated during thawing from foreign matter, pests or poor personal hygiene and handling.

Controls and monitoring when thawing frozen food

  • plan ahead, and allow sufficient time to thaw potentially hazardous food in the refrigerator or
  • cool room. Some food can take as long as one or two days to completely thaw;
  • alternatively, thaw potentially hazardous food in the microwave. However, there may be uneven heating of the food using this method;
  • remember to thaw raw frozen food on a shelf below ready-to-eat food. This will ensure that cross contamination (the juices from thawing food falling onto ready-to-eat food) does not occur;
  • keep all food protected, covered, wrapped or in a food grade container while thawing;
  • do not re-freeze thawed food;
  • check that ready-to-eat foods are protected from cross contamination by thawing foods;
  • small portions of raw frozen meat and fish may be able to be safely cooked without complete thawing, however, large portions of food should be completely thawed before cooking.

Corrective actions when thawing frozen food

  • do not use potentially hazardous food until it is completely thawed;
  • throw away thawed potentially hazardous food that has been left to stand at above 5°C for more than four (4) hours;
  • throw away food that has been contaminated during thawing;
  • throw away any food that has been frozen more than once.

Effective Food Safety Supervisors ensure that frozen food is thawed safely and in accordance with Food Standards.