If you store canned food at home for a rainy day, either factory can stuff or produce that you have canned yourself, you might have wondered if there is a way to get even greater shelf life out of it.
Have you ever considered freezing your canned food? If freezing extends safe storage life, and so does canning, maybe doing both together will give you the best of both worlds. So is freezing canned food a good idea?
No, freezing canned food is not a good idea. Freezing any canned food is highly likely to burst the container, or at best dangerously compromise the seal. This greatly increases the risk of food poisoning when the food thaws.
There is no good reason to freeze canned food, ever. Doing so is likely going to be a waste and could wind up getting you and anyone else who eats it seriously sick.
That being said, there’s plenty more you should know about the topic and even a way that you can safely determine if frozen, canned food is safe to eat or not. Keep reading and I will tell you everything.
Can You Freeze Food in a Can?
No, you cannot freeze food in a can. Actually, you can, or may, but you shouldn’t.
Freezing any kind of canned food is very likely to destroy the container or at the very least compromise the seal that helps preserve the food for the long term.
You can freeze food, or you may can it, but you should never do both. Will get into the reasoning behind this determination in the rest of this article. All you need to know for now, is that you shouldn’t do it!
Can You Freeze Factory-Canned Food?
No, you cannot freeze factory canned food. Even though it comes in metal containers with welded or otherwise permanently attached lids, freezing canned food means the moisture content within will likewise freeze, expand, and dangerously bulge or even burst the can open.
It is far more likely that the lid will fail at one or both ends, even if it is very small, thereby allowing in air and moisture which can cause dangerous bacterial contamination once the can thaws.
Can You Freeze Home-Canned Food?
Nope, you cannot freeze any food that you can yourself either. Freezing home canned food in traditional glass jars is an even worse idea than freezing factory canned food.
Glass jars will readily crack or shatter entirely as the moisture content inside them freezes and expands.
Also, the two or three-part metal lid of a home canning jar is far more vulnerable to compromise, so at best you’ll definitely be losing integrity even if, somehow, the jar doesn’t shatter.
Freezing Canned Food Will Likely Burst the Container
Although most canned foods are either canned in brine or in their own juices, all of them contain water. Water, as you doubtless know, expands when it freezes. Upon freezing, the volume of water will increase by about 9% as its density decreases.
Inside a sealed container, this results in a drastic increase in internal pressure. The formula is fairly complicated and I’m not a math nerd, but suffice it to say that precious few rigid containers will be able to withstand this massive increase in internal pressure.
As mentioned above, this results in bulging, cracking, shattering, leaking, or outright bursting.
That is bad enough, as it is usually ruinous and results in quite a mess to clean up. However, something far more insidious might happen instead.
If it Doesn’t, It May Compromise the Seal
Chances are you already know that pressure typically tends to take the path of least resistance. Considering a closed system like a sealed can or glass mason jar, chances are good that the path of least resistance is going to be via defeating a seal.
For a metal can, this will be along the rim at the top or bottom. On a glass jar or home canning setup, this will be between the lip of the disc and the band. In any case, once structural integrity is lost the food will no longer be properly preserved.
This is a major problem if the can is allowed to thaw. The leak might or might not be readily apparent, but in either case air and moisture will be allowed into the can.
There, it will begin a reaction that will give rise to bacteria and result in spoilage. These bacteria can also result in severe food poisoning, and arguably the worst among them all is the threat of botulism.
Botulism Can Kill You
Botulism, to put it lightly, is hardcore. Although rare it has the potential to easily be fatal particularly if contracted by those who are young, old, or already dealing with a compromised system or other persistent illness.
Botulism is caused by a particular toxin that is produced by a specific type of bacteria, clostridium botulinum. Although the bacteria are present in dirt and water alike, it is particularly common as a foodborne hazard.
Most notably, the toxin produced by the bacteria is only created when the bacteria are in a low oxygen environment within a certain temperature range.
As you might have guessed, this is particularly common in canned food, particularly that that is improperly prepared or one with a compromised seal.
Upon ingestion, symptoms will develop rapidly and most worryingly target the cranial nerves. Drooping of the eyelids, double vision, a slack expression, dry mouth, difficulty swallowing and lightheadedness are all characteristics.
Resulting low blood pressure and blackouts are also common and certain variations of the toxin cause vomiting, nausea, and loss of coordination.
Eventually, muscle weakness spreads from the head throughout the entire body, beginning in the lens and then eventually moving into the trunk which may affect the respiratory muscles and can cause total respiratory failure. Notably, it does not cause a fever.
Botulism is no joke, and although eating a dodgy can of food might only leave you with screaming diarrhea and an upset stomach if you are lucky, the consequences could be far, far worse.
Don’t Eat Unknown Frozen Cans of Food
If you are not perfectly aware of the disposition of a previously frozen can of food, throw it out. No exceptions. The consequences could be that serious.
The reasoning behind this is that you cannot be entirely sure if the can of food was frozen and has remained Frozen the entire time, or if it froze, thawed, and then froze again any number of times. If it froze and then thawed, the stage is set for food poisoning.
However, any canned food that has been frozen and remains frozen the entire time may be salvaged.
Though the seal of the can has ruptured, the freezing of the food will have preserved it as normal, so long as it was not allowed to thaw again.
So long as you take care in following it and then heating it to a suitable temperature, all should be well.
But, there are probably few situations where you will be privy to this perfect knowledge.
If you come across a frozen can of food that was left inside a vehicle or inside of a pack and exposed to freezing temperatures, for instance, you may not know just how long it was kept frozen and if it was kept frozen the entire time.
For that reason, you don’t want to take any chances. However, if you decide to change it you must thoroughly inspect any can of food for signs of rupture.
In my opinion, if the can is bloated, if you see any rust spots, obvious discoloration on a label or around a seam, or any visible spots of fuzz or slime, you should not risk it.
You Can Safely Freeze the Contents of Cans, Though
Now, for all of this talk and multiple warnings about the dangers of eating canned food that was frozen, you should know that it is entirely possible to safely freeze the contents of any canned food, whether or not it was factory canned.
All you need to do is open the can and decant the food, draining off any juices or brine. Then, simply place the food in an appropriate container or bag and place it in the freezer to freeze as normal.
Considering the moisture content of most typical canned foods frosting and freezer burn are definite considerations, but you won’t have to worry about the container compromising due to the freezing process.
Tom has built and remodeled homes, generated his own electricity, grown his own food and more, all in quest of remaining as independent of society as possible. Now he shares his experiences and hard-earned lessons with readers around the country.
Find out more about the team here.