bulging can of food

Bulging Canned Food Lid Spells Trouble…

Have you ever encountered a bulging can of food? I’m talking about canned food from the grocery store. More specifically, a bulging or bloated lid. Although rare, I just found one in my own food storage where I noticed the lid was bulging out a bit. I want to share two short video clips and a few photos of the bulging can / lid. Hopefully it will raise some awareness for your own health and safety!

Bulging Can / Lid Indicates Bacteria Growth

A can of food that’s bulging is bad news. Do not eat it! It likely means that there’s some sort of bacteria growing inside.

Here’s why I’m posting this… Sometimes it may go unnoticed. The bulge might be subtle. Other times more obvious. You need to always pay attention to this when you’re ready to open a can of canned ‘whatever’. Why? Because the bulging is likely being caused by bacteria inside the can. And it could make you sick, if consumed.

Grocery store canned food is pasteurized. It’s professionally processed to kill off any harmful bacteria. The food inside remains under a slight vacuum inside the can. This vacuum kind of sucks-in the lid.

When I grabbed this particular can of food, I immediately noticed the lid was bulging. Upon handling the can, my fingers noticed something wasn’t quite right. Well, my brain noticed via the sensory input from my fingers… It just happened automatically. I wasn’t particularly looking for a problem. I instinctively knew by the feel of it. Maybe we all ought to pay better attention, especially if we have older food storage (e.g. food storage preparedness).

Typically, I’ve found that most grocery store canned food has a manufacturer best-by date of about 2 years. This does NOT mean the food goes bad after 2 years. Actually, it will last much longer! I’m not going to get all into “best-by” or “use-by” dates because I’ve already written about it. If you’re interested, I will link that article below.

With that said, this can was 3 years past. It had escaped my view. I had several others of the same vintage which were fine. But not this one…

Picture of Bulging Lid of Canned Food versus Normal Can

You can see that the lid is convex, or curving outward. Compare it with the next photo of a normal can/lid.

The next photo shows the lid of a normal can. The lid is concave, or curving in. That’s because the inside of the can is pulling a vacuum on the lid. See the difference?

How to Tell If A Can Of Food Is Bulging

Here’s a short video clip of me popping the lid in and out. You can hear the click or pop when I press on the lid. It’s obvious that there’s pressure inside the can, rather than a vacuum. That’s not good…

Opening A Bulging Can Of Food

I decided to open it with the can opener. Here’s the video clip. You can hear the lid make a noise a few seconds after starting the can opener.

I sniffed the food after I opened it. It smelled seemingly normal. However, when in doubt, throw it out! There was definitely something ‘bad’ going on with this one.

So for all of you who may have a built-up storage of various canned foods (among other things) for preparedness, do pay attention to your cans, especially older one’s. We try our best to rotate through so that they don’t get too old. 2 years is a pretty good rule-of-thumb. But some don’t always get consumed within that time period – for various reasons.

[ Read: Use-by, Best-by, Sell-by Dates ]

[ Read: How to Tell If A Dented Can Is Safe ]


  1. Acidic foods are the worst. That can you showed looked like some sort of seasoned/barbeque type of meat. I have thrown out several in the last few years of the same. Then, again, I mention vienna sausages, finally got Mr. to stop buying them, for what ever reason they have not lasted well at all. Chili does not last either nor pineapple. These were #10 cans. If you want some pineapple get dried or maybe re can in glass? Get all you can in glass. Acid degrades the can linings which might contribute to the degrading of the food.

    1. Mrs U,
      Like the idea of drying pineapple for long term. Re-can in glass? You still have a metal lid exposed to an acidic atmosphere inside the jar.

      1. Minerjim,
        I use Tattler lids (plastic with a separate rubber seal) instead of traditional metal canning lids when canning acidic things and haven’t had a problem.

      2. If you have access to a freeze-drier, pineapple dries REALLY, REALLY WELL!

  2. Pineapple that is canned will require being used up before the lid decides to bulge. Yes, I have had that happen to a couple of cans that I purchased. Did not bother opening them just placed it in a smaller plastic bag then went into the trash.

    My health is not worth the chance of eating something which could land me in the hospital or dead.
    Yes, dead. I have a news article of a young lady who worked for my great grandmother. She opened up a jar of peas the lid most have looked sealed, she did a taste test is the only thing they could figure out. My grt grandmother found her dead from food poisoning. They discovered the second jar of peas she had pulled out of storage where the lid was raised (bulged).
    When in doubt–toss it.

  3. The most troublesome as some of you have mentioned, fruits, like peaches, also tomato paste for some reason, occasionally will find an old can o this or that lookin sorta questionable, sometimes they look fine but are shot when you open them, rarely though, knock on wood, ive been working on being less picky

  4. All canned food has limitations: In the 1980’s somebody found vintage Korean Was C-rations that made their way to fire camp in San Bernardino. Thousands of firefighters got sick and the rest of us got in the habit of checking the date and checking the seal of the cans for broken seal via pushing in to listen for the: “ka-tunk” of a blown seal. There was a refuse pile of reject cans that was about 5 feet tall. Such a waste. I do not know of any use for bad, canned food.
    Food poisoning is no fun and can be quite messy. Despite the stories, people do not just die from it. The will frequently puke and sh!t themselves into dehydration. NRP’s 600 rolls of TP may not be enough for times like this. I have a fair amount of canned foods in my inventory. I try to rotate it through an annual basis.

  5. Opened 4 large gallons of whole peeled tomatoes from 2008…they were fine. Cooked them down with onions peppers garlic sugar and Italian spices made 12 qts of spaghetti sauce.

  6. I won’t even OPEN a bulging can! “Testing” food from cans like this is akin to being adrift in a lifeboat and drinking seawater! You are GOING to lose!!!

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