Why can’t you freeze uncooked thawed frozen food?


Frozen food packaging always advises against re-freezing uncooked food once thawed. Is it a bacteria issue?


Yes and a quality issue. But anytime food passes through the danger zone(41-140) bacteria multiples rapidly. Freezing it again doesn’t kill all of the bacteria.

You can. It’s just a general rule to mitigate the amount of time that food spends in the “danger zone”, that is the temperature range that allows bacteria to grow quickly to an unsafe level.

If you thaw it fast, like in water. Or slow but controlled, like in the fridge then you can refreeze it.

Bottom line is you should always know how long the food has spent above 4 or 5 degrees C, and it should be less than 4 hours if its meat fish or dairy.

Freezing doesn’t kill bacteria it just slows their growth, in addition some bacteria can produce toxins which can be very dangerous and even cooking won’t remove the toxins. https://youtu.be/9aPZGF4gQag

As it goes from hot to cold to hot and back again, it spends time in between at lukewarm, and lukewarm is where bacteria grows so you don’t want your food to spend much time there if you can avoid it.

It is a safety issue as others have pointed out.

Also most people don’t own freezers that can flash freeze or freeze things quickly – which is what is done in commercial frozen food preparation. The ice crystals that form in a conventional freezer are larger and therefore penetrate cell walls. The next time you defrost that item, it will leak a lot of fluids losing a fair bit of nutrition and texture as a result. So this impacts the quality of the food item as well.