How is it that you can refreeze some foods that have been previously frozen and defrosted (by a supermarket) but you cannot refreeze defrosted items at home?


Today I bought some food that I had planned to freeze for use on another day. On the back of the packet it detailed that it had previously been frozen but thawed under controlled conditions and that it was safe to refreeze. I had always thought you couldn’t refreeze once thawed. How can supermarkets do this differently to me at home?

If at all contextual, I live in the U.K. and it was a curry.

In: Other

Basically the issue with refreezing is the water inside the food. When an item is initially frozen the water expands and widens the holes it is in, then when thawed the water comes out of those holes and can freeze somewhere else causing damage. This is the root cause of freezer burn. Items frozen under controlled conditions tend to be frozen anhydrously so they don’t have the same issue.

Many items need to be frozen in a particular way that home freezers can’t replicate. A common method is flash freezing, which is generally done at -320F using liquid nitrogen. Freezing it this fast prevents large ice crystals from forming and damaging the food.

Freezing and thawing by itself doesn’t make a food ‘unsafe’ but it will have a big effect on the flavor and texture. Water expands when it freezes so freeze/thaw cycles turn things into a mushy mess.

Most frozen food at the store has been flash frozen. Making it safer, higher quality, and longer lasting. You don’t have this ability at home.

The package said “controlled conditions,” you also do not have this ability at home. This gives your food a higher chance of growing something dangerous to you. Most likely, it will just ruin the quality of the food, not make it dangerous

It is likely not the supermarket, but the manufacturer. The supermarket just stores the food created somewhere else

There isn’t anything inherently bad about freezing, thawing and refreezing, as long as it is done carefully so that you do not contaminate the product by handling or air exposure that would increase the bacterial count while also making sure that the time and temperature is within permisible parameters (usually means product is never over 5°C for over an hour).

Freezing a product will, on the other hand, affect the physical characteristics, specially if thawing rapidly. For instance, cells will rupture and meat will be drier and tough, strawberries liquefy, ice cream will form crystals, just to name a few examples.

Thank you all! I’ve always been a bit wary of freezing and defrosting food. Good to know I might not necessarily do myself any serious damage