Canned Food Gone Bad – Do You Know All 8 Signs?

Canned food is a vital part of any good survivalist’s toolkit. The process of containing food within a can is done to help to allow it to last far longer than it would otherwise last in an ordinary container, or left out in the open air. 

Canned food is also easy to store away in a strategic way, so you can easily stock up for days and even weeks ahead of time, in case you need some easy food that you can depend on. 

Canned Food Gone Bad – Do You Know All 8 Signs

However, as useful as canned food can be, and as long as it can last, it does not last forever. Eventually, even canned food will go bad, but it can be difficult to tell when it has done. What are some of the surefire signs that can help you to identify bad canned food? 

If you are worried that your canned food may have gone bad, or you are doing a quick check of your current stockpile, then why not check out our 8 surefire signs that will let you know if your canned food has gone bad? Read below!

1. Has The Can Become Misshapen?

One of the earliest signs that you may notice when canned food has gone bad is that the shape of the can seems off. Check for signs that the can may be bulging, and that metal may be stretching.

Sometimes it can be difficult to tell if a can is swelling just at a glance, but one way to find out for sure is to check the top of the can. Apply light pressure to the top of the can, and notice whether it pops, or moves when you push it.

If you notice that your can is swelling or bulging, then it is very safe to assume that it has gone bad. This is because it is full of gas that comes about when bacteria breeds. The toxins in this gas are very harmful, and they are what lead to food poisoning.

2. Check For Loud Hissing Sounds

Naturally, whenever you open any kind of canned food, it will release a hissing sound of some kind. This is caused by the vacuum seal protecting the contents being released. However, if you notice that the hissing is louder than usual, or that it lasts much longer, then that could be a sign that the contents have become spoiled. 

Louder hissing is caused by the gasses that are released by the bacteria that have been allowed to propagate in the can. Thus, if you notice loud hissing, you should throw the can away as soon as you can. You should also avoid opening it any further, so as to help keep anymore of the bacteria from being released.

3. Spraying Liquid

Another problem that can be caused by pressure building within the can is that liquid may spray out. When there is excessive pressure inside of a can, then the contents may spray out when you break the vacuum seal.

Once again, this will be caused by bacteria releasing harmful toxins in the form of gas as they multiply, so if the contents from the can spray out, then it is a surefire sign that those toxins have been released, and thus you should throw the can away as soon as you can.

4. Corrosion

Naturally, if you were to ever see signs of corrosion across the surface of the can, then it should be cause for concern. Food cans are designed to last a very long time, thanks to the materials used to make them.

Thus, signs of corrosion should actually be very uncommon. If you notice them then it could mean a number of things.

Corrosion may have happened as a result of being stored improperly, such as in direct sunlight, or in moist or otherwise unprotected areas. You should aim to store food cans in dark and isolated areas to allow them to last longer.

If you notice any signs of corrosion on your food cans, then you should throw them away as soon as possible, because the corrosion could have allowed small amounts of bacteria in.

Canned Food Gone Bad – Do You Know All 8 Signs

5. Leaky Can

If your can is leaking its contents, then it is completely beyond saving. If you grab one of your food cans and you notice that it is moist, or that its contents are spilling out, then you should probably throw it out.

However, you should also try to determine how long the can may have been leaking for. If you can tell that the can has only been leaking for about the last thirty minutes, then it should be fine.

However, if you find a leaky can towards the back of a set of cans, then it can more safely be assumed that it has been leaking for some time. 

You should also check for distinctly sticky spots on your cans, which can suggest that, while there may no longer be a leak, there once was!

6. Bad Smell

If, when you open your can you notice that it releases a pungent odor that you would not otherwise expect, then you can safely assume that the contents have been spoiled. 

You should also try to notice distinct metallic or acidic smells, as they can be a direct sign that the food inside has spoiled, or that bacteria has spread to dangerous levels. 

And it goes without saying that if a can of food smells bad before you even open it, then it should be thrown away as soon as possible!

7. Bubbles 

Now, it is important to mention that canned food may naturally release a small number of bubbles upon being opened, as this will be caused by the vacuum seal suddenly being opened. 

The kind of bubbles you want to keep your eyes out for are rising bubbles that are caused by gasses being released within the liquid in the can.

If you notice these rising bubbles, then it is important to discard the can right away, as they will have been caused by the toxin-filled gasses that are released by bacteria. 

8. Dents

Look all over the can to try to see if there are any significant dents on the surface.

Dents are particularly problematic as, though they do not allow bacteria directly into the can, they do cause the pressurized air within the can to be moved around very suddenly, which completely alters the airtight seal, making it less effective.

Large dents in your cans could have opened the floodgates to bacteria, and you may find that the food inside has spoiled much faster than usual!

To Wrap Up

There you have it! Those are some of the most easy ways to identify whether your canned foods have gone bad. Most of them are related to excess pressure within the can, which is caused by gasses being released by bacteria deep inside.

Thus, if you ever notice signs that there is an excess of gas in your food cans, you should throw them out before consuming them!

Frequently Asked Questions

Can You Get Sick From Eating Expired Canned Food?

Many canned foods will actually last much longer than their stated ‘best by’ dates, thanks to being vacuum sealed. 

However, if you were to eat the contents of a can that had gone bad, then you may most likely experience a stomach ache.

What Should I Do If I Ate Expired Food?

If you find that you did consume expired food, don’t panic. The most likely result will be a stomach ache within 24 hours of consuming the food. At the very worst, you may be poisoned by high levels of bacteria but this can be sorted with a visit to a doctor.

Can You Eat Expired Food If It Hasn’t Been Opened?

Yes. ‘Best buy’ dates are actually usually printed onto food as a guideline for quality. The food will taste best before the date, but it won’t be unsafe to eat it after the date.

Tim Roth
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