Most foods previously frozen, thawed and then cooked can be refrozen as long as they have not been sitting at room temperature for more than two hours. Remember that freezing does not kill bacteria, only prevents the microbes from multiplying. So thawed food will have some bacteria that can multiply at room temperature, meaning that if the food is refrozen, there will be an increase in bacterial count by the time it is thawed again. This becomes a non-issue if the thawed food is reheated to an internal temperature of 75 degrees C.
Thawing should always be done in the refrigerator, not at room temperature. Remember that if you thaw at room temperature, the inside can still be frozen while the outside reaches a temperature where bacteria can multiply. Low moisture products such as breads or cookies can be thawed at room temperature because bacteria have a hard time frolicking without moisture.
Microwave ovens generally have a defrost mode that works well; best to use a glass or ceramic container with a cover that allows steam to escape. Frozen food can also be reheated directly in a regular oven, again making sure the internal temperature reaches 75 degrees C. This usually means heating at 175 degrees C for a time that is longer than the original cooking time for that food.
When refreezing, food should be placed in containers that can be filled to the top as much as possible so that there is a minimum of air space. Unsightly freezer burn occurs when moisture from the food evaporates into the surrounding air space. The less air space, the less likelihood of freezer burn, which is not a health risk, but affects taste. Freezer bags are great because you can squeeze out the air.
Don’t freeze acidic foods such as tomato sauce in aluminum foil or in aluminum containers because aluminum can dissolve and taint the food. Green salads do not freeze well. When water freezes into ice, its volume expands and that destroys cells, mangling the texture. Again, not a health hazard, but a matter of mushiness.
Want to engage with this content? Comment on this on our Facebook Page!