I got a one of the two packs of Kirkland sliced ham at Costco. The first pack was fine, but the 2nd pack has swollen up like a balloon. The expiration date is 9/13. My inclination is to throw it out, but I thought I would check if there is a harmless explanation for it.
I would take it back to the store and get a refund. I suspect the culprit is some kind of bacteria or yeast.
Throw it out. Don’t even open it first. Sure someone might have injected it with air using a syringe and then sealed the hole, but nasty things are incredibly more likely. Why take any chance.
There are harmless explanations, but unless you have a home bacteriological test kit you *must *assume it’s not harmless. Those are airtight packets, which means that they can grow botulism. There’s no such thing as trivial botulism poisoning. Even minor cases usually cause permanent damage.
Throw the stuff in the bin and make sure the neighbourhood scavengers can’t get at it… or not depending on how much you like raccoons and stray dogs. 
Most bacteria that grow on anaerobic meat are fairly harmless. They impart an unpleasant taste to the meat but they won’t hurt you at all. Most of the ones that are harmful will only cause a stomach upset. However there are a few that cause really nasty symptoms: blindness, brain damage, insanity, kidney failure and of course the ever-popular death. In some cases one strain of a species is harmless an another causes irreparable organ failure. There’s just no way of knowing which one you have without a bacteriological test kit.
Are you feeling lucky?
I guess I could try. I’ve never asked for a refund on **half **a package of ham before. The trouble is the gas driving to Costco costs more than the ham.
After reading the Ham Storage Chart, I wonder if I should freeze the other half of the package next time.
It’s trying to establish dominance over you. Don’t let it. You are the boss of the home.
No argument with the “throw it out” advice - that’s exactly what I’d do. But what is it that causes the pack to swell up? In other words, what’s happening to the meat that produces these gases?
No I don’t feel lucky. I’ll double bag it and not take it to the curb until the morning when the trash men come.
And punch it in the nose if it tries to eat your dog?
This happened once before to me at Costco. I think I’m buying my sliced ham at Sams from now on and keeping the unused half in the freezer. The ham looked fine when I bought it. I didn’t notice any swelling at all until I went to get it out of the refrigerator.
Bacteria decompose the meat.
Note this may make you lose your appetite.
I was putting a freezer bag over it and noticed there is a lot of fluid in the container. I think I’ll take a few pictures and email a note to Costco HQ.
To elaborate:
Some bacteria, deemed heterofermenters, turn carbohydrate into carbon dioxide and acids. Some of these also can make the most evil snotty slime. Yeasts tend to do carbon dioxide & ethanol instead. Other bacteria turn protein into gasses.
The odds of this being botulism are slight since sodium nitrite inhibits Clostridium botulinum. Plus, most strains of this don’t grow at refrigerator temps.
Another explanation, less likely, is if a fresh-cooked cold-cut roll is chilled with carbon dioxide “snow”. If packaged very speedily, the sublimation causes the package to swell. This is more common with raw meats sold frozen.
Would I eat it? Hell, no.
Right, so they (the bacteria) kinda like, eat the meat? And turn it into methane and hydrogen sulphide and so on? Or rather, excrete these gases in the process.
In which case I should probably try killing that bloated meat package with fire.
Nuke it from orbit. It’s they only way to be sure.
The gasses created during bloat could explain the condition of the package.
These pictures are nothing. I worked on the software for a wound management system. There were some color plates you didn’t want to look at after lunch. The checklists were bad enough. Is the wound oozing? What color is it oozing? What is the smell?
I had this happen once with a package of store-brand lunchmeat. It was the kind that is in a reusable gladware-like container, with the meat sealed in a plastic envelope inside. It was fine when I grabbed it from the case, but by the time I got to checkout, the envelope had puffed up and popped open the plastic container it was in.
I figured it was just cold air expanding once it was outside the refrigerator case, so I took it home anyway. And it didn’t deflate in the fridge there. So we tossed it.
My theory now is that something was brewing, the warmth let the existing gases expand, and also let the “brewing” get going nice and strong.
On another recent occasion, I’d gotten prepackaged fresh pineapple spears (individually wrapped) for box lunches. A day or so later, I grabbed one of the remaining ones - and noticed its bag was puffy too. As nobody had died from eating the others, I opened it and took an experimental bite. Bleah - tasted like it was fermenting. I spat out the bite and tossed the rest. The taste seems to have done me no harm.
Don’t throw it out. That’s like throwing away money. Take it back. They will exchange it or give you your money back. If you aren’t going back to Costco for awhile, throw it into your freezer until you do.
Instead of this, you should call Cosco to ask about their return policy and keep your receipt if you still have it. I worked at a grocery store for 2 years and there is NO WAY I would rather have you bring in rotten meat than to just take your word for it.
Worst story: Some lady bought some carrot juice that turned and wanted a refund. I said “Sure no problem” and then she proceeded to say “Look, here…” and I said “NO NO NO!” as she proceeded to open the container of rotten carrot juice and spill it on my counter after I JUST told her she could have a refund. :mad:
I found this page because I had a similar question about a package of shredded cheese that had “puffed.” I’d always heard that cheese does not grow any “toxic” molds, at least, not the ones you can see. In this case there was nothing visible and the smell was fine – just that the bag was puffed a bit (but not to the point of looking like it was going to explode or anything.) I figure this is “probably” OK, at least to cook into a recipe, but I can understand that there is always some concern with this. Any opinions. I like that this thread has people discussing what is really going on biologically – that is what I’m trying to learn about.
Regarding the earlier post about “returning bad food items to Costco,” they are very good about this. In fact, I’d say you don’t need to bring the whole item back, just cut out the portion with the label (including the UPC any date codes, etc). You can put that into another plastic bag. They will refund you without any problems, at least, that is my experience. It will be best if you still have the receipt, though it doesn’t seem to be absolutely necessary for Costco because they have access to all your purchase records based on your membership number. (This is also how they prevent people from abusing the system – because all returns are tracked.)