Is it safe to leave canned goods – ordinary foods, like soup or tuna – in below freezing conditions?
The situation this came up in was ‘forgetting’ and leaving groceries in the car overnight in a cold climate.
I’m assuming that liquids in bottles are likely to burst their bottles, and probably any fresh produce will turn into ‘frozen’ foods, with results from “okay” (peas and such) to “horrible” (lettuce and such.)
But what about that can of Progresso soup?
I know from personal experience that if you put cans of soda in the freezer too long, the cans rupture and cause a major mess in your freezer. But those are really light-weight aluminum cans. What about ordinary steel (?) cans? Are they going to survive? or will the welded seams likely fail?
And, if the cans themselves survive, are the contents safe to eat later on, after they’ve thawed of course?
Hmmm. Does this mean people with un-winterized cottages must be sure to clear out all food stuffs when they close up for the winter?
The skightly stronger can wont help resist the expansion of ice. There’s a fairly famous experiment where freezing water will break a very substantial metal container.
what might help:
Steel cans often have expansion ridges built in
The contents might be salty
Yes. Canned potatoes (I think these were whole) are normal cooked- potato texture. They became literal stringy purée within the can after freeze-thaw. The ice crystals that form exploded the physical structure of the potato.
Ah. Very interesting, so the food is safe to eat if the cans didn’t rupture, but the contents will likely be of lesser texture appeal. Probably will vary on how much it changes. I mean, something like deviled ham is pretty much mush anyway, but those potatoes sounded nasty.
Good to know, thanks.
Only if the cans didn’t rupture from the perspective of the little nasties you don’t want to eat. What you have is no longer canned food, it’s frozen food now and the frozen food rules apply (at least IMHO).
