10 Signs Your Canned Food Has Gone Bad

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Do you know how to tell if the can or jar of food in your stockpile is safe? Some dents are ok, but these 10 signs mean that your particular can or jar is not safe to eat.

1. Bulges in the lid of a jar, or the lid or sides of a can are a sign that something is seriouslywrong with the contents. Canned food should not create a bulge. If you see a bulging lid or side, it’s a sign of pressure from gas, bacterial activity and spoilage. Don’t eat the contents of any bulging can or jar with a bulging lid.

2. Excessive pressure release when opening a jar is a sign something is wrong. It’s normal to hear a light “whoosh” when opening a sealed jar, but a lot of pressure or even a surprising amount of pressure releasing on opening is not a good sign. It could mean gas has built up inside the jar as a byproduct of bacterial activity. If something doesn’t seem right, throw out any can or jar that does this.

3. Bubbles are a sign of spoilage. Bubbles usually indicate some kind of fermentation, a bacterial process which can be perfectly fine IF intentional and under certain specific conditions, and makes excellent pickles, wine, beer and other foods.

However, unintentional fermentation is rarely a good thing, and under low-acid or low-oxygen environments some bacteria can lead to deadly problems, including botulism. If you open a can or jar that’s been sitting on a shelf and you see bubbles, something isn’t right.

4. Foam is an indicator of bacterial activity. Botulism and other dangerous bacteria can survive (and even thrive) in very low-oxygen environments like canned food.

5. Cloudy liquid that should be clear is another sign that food may no longer be good.

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6. Signs of mold on the underside of a lid means the food should be discarded. No matter what the color is, mold on the underside of a lid is a bad sign, and the food in that can or jar should not be eaten.

7. Inadequate seal. If a lid can be pushed up and down, it’s not safely sealed. When you first can a food, the lid is sucked down as the jar of canned food cools. You should not be able to depress a lid and have it pop back up. That indicates it did not seal properly. Unsealed and unrefrigerated jars are not safe to eat.

8. Leakage means the container is compromised. If there are traces of food on the outside of the container, it likely leaked from inside the same container. If there’s a leak, the seal is compromised, and the food is likely unsafe. When in doubt, throw it out.

9. Does something smell funny? If the contents of a can or jar smell “off” or unusual, or somehow different that you remember, then the food might have gone bad. If it doesn’t pass the sniff test, throw it out.

10. Rust on a can is a sign the container may be compromised. If you can clearly see the can is fine, then it’s probably ok, but your containers should not be getting rusty. Evaluate your storage location and rotation plan to ensure you aren’t keeping food too long or in less-than-ideal conditions. Rust is a clear sign that something isn’t ideal.

Be smart and bon appetit!

What tips would you add? Share your advice in the section below:

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