Sometimes when preparing to eat canned goods, I realized that it has already expired. I am hesitant to throw it away because it may still be edible.

Question: Does cooking expired canned goods make them edible? Assume that it expired no more than one month ago. Some say yes, because it only affects the quality of the product. Some says no, because it is very dangerous and not worth risking.

I want to hear this from experts. :)


1 Answer 1


If the food is spoiled, no, it's still unsafe, because cooking may not destroy toxins that have built up over time. Botulism is a particularly nasty one that will not be destroyed without pressure cooking, and can really, really mess you up.

... but in the case of canned goods, if the cans are still intact (no punctures, rust, etc), and the canning process was done correctly, the food inside will remain safe even if the quality of the food may have changed, which is what the 'use by' or 'best buy' dates typically signify for canned goods. (some will argue it may change for the better).

In the scope of storage lifetime for canned goods, one month is relatively nothing. It's more significant what temperature it had been stored at up until now, as canned goods age significantly faster at warmer temperatures. I personally wouldn't hesitate to eat stuff in a one-month past 'use by' date can (or even a year past), but I'm in a more moderate climate than you are.

If the cans have been in a relatively cool place (not in direct sunlight, or stored near a heat source), it's probably okay. Look for obvious signs of puffiness, and listen for air escaping then you open the can (entering is okay ... escaping is bad). If you hear lots of hissing after breaking the seal on the can or if it smells or looks off, just pitch it and don't risk it. (as would be true for canned goods still within their 'best by' date ... although then you might be able to get a refund from the company if you contact them)

And, to cover myself from potential litigious behavior : If you're immune supressed, I wouldn't suggest you take the risk. I also wouldn't suggest serving it to others ... although the risk may be low, other people should get to make an informed choice if they wish to risk it. (older people and small children are more likely to have issues)

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    I was under the impression that a properly canned product in an undamaged can is safe indefinitely, and the "use by" date is merely a suggestion for optimal quality, not safety. Sep 25, 2014 at 1:11
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    @CareyGregory : assuming it's been canned properly, and hasn't suffered any damage (I should've mentioned signs of rust) ... yes, that's likely true. See cooking.stackexchange.com/q/47048/67 . It's more a 'cover my ass' because I don't know what conditions of storage might be.
    – Joe
    Sep 25, 2014 at 1:46
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    The OP seems to think the "use by" date refers to a safety limit and your answer reinforces that (mistaken) belief. I think a little clarification would improve your answer. For example, I don't think it matters if cans have been stored in hot climates. The only thing that really matters is that the integrity of the can is intact. Sep 25, 2014 at 1:57
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    @CareyGregory : okay, modified.
    – Joe
    Sep 25, 2014 at 2:30
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    Regarding Botulinum, it is not the bacterium that causes the poisoning, but the toxin that it produces. Heating the food above 80C (or better boiling it) for a few minutes will definitely destroy the toxin, making the food edible (if the Botulinum toxin was the only contaminant!). Also note that if the food is acidic (pH below 4.6) there is no risk of Botulinum poisoning. That's why most canned goods have the pH lowered by the addition of acidity regulators, like vitamin C (also known as L-ascorbic acid E300). See also fsai.ie/faqs/botulism.html
    – Kuzulin
    Jan 8, 2017 at 6:53

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