Canned Food Gone Bad – Do you know all 8 signs?

How can you tell if canned food is bad?  Do you know the signs of spoiled canned food that might be deadly?  There are several ways harmful bacteria can contaminate canned food.  In the United States, there are over 100 cases of botulism are reported each year.  This harmful bacteria can cause serve illness and even death.

Is there a way to tell if canned tomatoes are spoiled?  A person can’t see or smell if a can is contaminated with botulism spores, however, there are other contaminates that can be seen and smelled.  The good news is that most of the signs that canned food has spoiled are fairly easy to recognize once you know what to look for.  Below are 8 warning signs of bad canned food.  If you are concern about a can or jar of food, don’t risk it!


Canned Food Gone Bad

Can you guess the 8 signs below of how to tell if canned food is bad?

1. A Lid that Bulges Moving Up & Down

This unsafe can of whole potatoes had been exposed to extremely cold temperatures and relatively hot temperatures in my garage, over a 6 month period.


2. Food Projecting or Exploding When Opened

Click here to see a YouTube Video


3. Rusting / Corrosion of Can

Rusting Can - canned food gone bad - Food Storage - Preppers Survive

This was pulled out of a house fire and it was covered with soot.  Soot and moisture corrodes metal.  Corrosion will eventually create holes that let in air and bacteria.


4. Leaking

Canned Food Gone Bad - Leakage

5. Dents

dented can - canned food gone bad - Food Storage - Preppers Survive

 Dents compromise the integrity of the air-tight seal which can expose the food to harmful bacteria.


6. Acrid Smell

If it smells pungent, acidic, chemical, or has an unnatural smell don’t eat it!


7. Rising Bubbles or Unnatural Looking Colors

bubbles - canned food gone bad - Food Storage - Preppers Survive

The picture above is of a well shook can of safe bubbles.  I didn’t have an example of unsafe bubbles so I thought I’d show you safe bubbles.  The bubbles to be watchful of are small rising gas bubbles.


8. Sound – Hisses Loudly When Opened or

No Sounds of Liquid Inside When Shaken

Hissing - canned food gone bad - Food Storage - Preppers Survive

A soft quiet hiss when the air rushes into a can you are opening is normal but a can that hiss loudly when opened is a warning sign.

– – – – – – – – –

So if a can is bulging, projecting, rusting, leaking, is dented, has a weird smell, looks funky, or hisses loudly DON’T taste it and handle it carefully!  “Contact with botulinum toxin can be fatal whether it is ingested or enters through the skin. Take care to avoid contact with suspect foods or liquids.” Carefully dispose of the contaminated food.

Other articles you might be interested in:

Powdered Milk Uses - Recipes Using Powdered Milk

Best Canned Goods for Starting Food Storage – Starter Kit


What Should Be in Emergency Kit- Power Outage Kit Picture

low budget prepping - Prepping for Beginners




About PreppersSurvive 130 Articles
Welcome to my site! My name is Nettie and I started this blog to provide simple tools to help Preppers.  I am a Girl Scout Prepper. “Be prepared! A Girl Scout is ready to help out wherever she is needed. Willingness to serve is not enough; you must know how to do the job well, even in an emergency" (the motto, in the 1947 Girl Scout Handbook). Being a Prepper has been a blessing to me, my family, and friends on more then one occasion. You'll find these stories throughout this blog.  You will also find prepper supplies checklists, prepper events, cheap food storage ideas, emergency heat sources, survival books recommendations, reviews on power outage lights, printable prepper pdfs, and articles on emergency disaster preparedness.  Click here to read more

2 Comments on Canned Food Gone Bad – Do you know all 8 signs?

  1. As to dented cans… if the dent is on the seam of a seam-type can, or a v-shape or significant dent on the rim, then it is potentially dangerous. Also, if the dent is deep enough to make the metal overlap. Other dents in the side like the one in the picture are safe.

    … I used to work in food salvage. These were the guidelines by the Dept. of Agriculture.

  2. Thanks for sharing these ways to look out for bad canned food. While canning is a great way to preserve food, it’s important to know what to look for in case it didn’t work as planned or has spoiled.

Leave a Reply

Translate »