How do we know what is still safe and what isn’t?
Refreezing food is not dangerous, the danger is that food can spoil before it’s refrozen or after it‘s thawed again but before being cooked and eaten.
Freezing food does not kill bacteria, so once thawed bacteria continues to multiple at the same exponential rate it was multiplying at before being frozen. This is one of the reasons to set your freezer to it's ideal temperature.
Refreezing also reduces quality because the already slightly damaged cells are being expanded with ice crystals again. This isn’t a big deal for meats or baked foods but is huge for rice, pasta, fruits and veggies.
Try to figure out how long things have been thawing/thawed to help you make a safe decision. And never feed a pet food you wouldn’t eat, they can get food poisoning too.
Toss it if
- Temperature went above 40F
- There is a bad odor
- You have any doubts the food is still safe
- Other foods have leaked onto it, especially meat or dairy juices. (And keep your freezer well organized to help prevent this.)
Refreeze food if
- It still has ice crystals. Use your best judgment here, something big like a turkey could be really warm and thus unsafe while there are still ice crystals in the cavity.
- Cook any raw meats that thawed but are still cold, under 40F (aka fridge temp), but not icy, before refreezing.
- Be careful with prepared/cooked foods, it’s best to reheat and eat them instead of refreezing them because of the risk of bacteria and the loss of texture.
When Refreezing food:
Label clearly so you know to use this item fast. I usually write something like “Do not thaw” if it can be cooked from frozen or “Use as soon as thawed” so I know that this item should be cooked as soon as it thaws.