IT’S A MYSTERY, The Case of the Inflated Mozzarella Cheese Bag. To be sure, this is no Nancy Drew mystery like the vintage Carolyn Keene books shelved in my living room. Rather, this mystery centers in my kitchen, on the second shelf of my refrigerator.
Preparing dinner recently, I reached into the fridge for a bag of shredded cheese. What I pulled out stopped me in my meal prep. I held in my hands an unopened, inflated 16-ounce bag of Happy Farms by Aldi low moisture part skim shredded mozzarella cheese. The bag looked like a fully-blown balloon with no air leakage.
What the heck? I’ve never seen anything like this. Ever. Not in an opened or unopened, fully-sealed bag of cheese. My initial thought was that the cheese was old and spoiled as I purchased it sometime ago. I keep multiple bags of cheddar and mozzarella cheeses on hand. But the “best by” date is December 22, 2022.
I needed to solve this mystery, or at least gain some insight. So I sleuthed online, leaning into the theory that bacteria growing inside that cheese bag produced the gas which inflated the plastic bag. That makes sense to me, but then doesn’t answer the question of how bacteria got inside an unopened bag of cheese.
Whatever the cause of this mystery, I did not eat that cheese. Rather, I returned it under the “Aldi Twice as Nice Guarantee” with the item replaced, money refunded. In these days of high inflation and soaring food prices, “inflated” has assumed a new meaning.
Before returning the cheese, I sealed the sealed cheese bag inside a plastic bag lest, for some mysterious reason, the bag exploded inside my fridge. As much as I appreciate a good mystery, I didn’t need a sequel, The Case of the Exploding Cheese Bag.
TELL ME: Have you ever seen anything like this in food packaging?
Minnesota Prairie Roots 
I was guessing that something was spoiling in the bag, but like you, don’t understand how it cam to be. I have had a ‘salad in a bag’ do this and it was well before the expiration date. also a box of almond milk, I returned both and did not use them but even the store seem baffled.
The Aldi cashier here was baffled also. It’s interesting that you’ve had this happen with two very different products also. Read on to the other comments I’m getting for a likely explanation.
Will do
My guess is that there was a mishap at the cheese factory – some contamination got in this bag. It happens, just, fortunately, not too often.
That would have been my guess, too, until I started reading comments submitted here.
I’ve had the bag inflate thing happen when hiking in the mountains. We buy a limp bag of Cheetos (our favorite) down in town and by the time we reach the trailhead several thousand feet higher, we’ve got a pillow (but no explosions yet). So, unless, Faribault is higher than I think it is, I’m sticking with my “bad cheese” theory. 😉
I lean towards your “bad cheese” theory also given Faribault’s location. Watch those Cheeto bags!
I have one now! I’m in Florida…gonna return it! Never seen such a thing
I felt the same when this inflated cheese bag happened in my fridge. So weird.
I have! I traveled from Oregon to Santa Fe New Mexico once. I was attending a trade show. I used to work for a company that manufactured beef jerky. I shipped the jerky out so it would be there when I arrived. What I found when I opened the boxes, is that ALL of the bags of jerky had blown up like balloons!! They were rounded rather that flat, just like your bag of cheese. From my understanding, the reason for the change was the change in altitude. Where I was in Oregon was at about sea level, while Santa Fe is located at high altitude. I know this doesn’t solve your cheese mystery, but that was the experience that I had with something like it. 🙂
This is so interesting. I never would have thought altitude could cause this inflation. Several other commenters agree with that theory.
Looovveee a good mystery – not one that implodes food all over my fridge though – right there with you on that. I have had salad bags do this and depending on the circumstances usually just toss or bring back to the store if can be returned. I worry about the bad mold in these situations. Glad it all worked out for ya. Happy Day – Enjoy 🙂
I especially liked Aldi’s return policy of refund and a free bag of cheese.
This is a common sight in mountainous areas. The high elevation (even just for a few minutes) does something with the air in the bag causing it to swell. Perhaps the truck who brought the cheese to Aldi’s came over a high mountain pass.
Other readers are suggesting the same. I wonder why it took weeks for this to happen in my fridge?
My first thought was a difference in elevation between your home and where the cheese was bagged. But, even if the cheese was packaged at sea level, Faribault isn’t at a high enough elevation (977 ft) to account for the inflation. (I don’t think.)
I’m hearing the same from other readers, Ken. So I think you all may be on to something.
While flying from the east coast to the west my sister lad a bag of Doritos blow up in that way. Obviously, her’s was due to a change in altitude.
Lorraine, thanks for sharing your sister’s experience. I am learning a lot from readers like you. I had no idea this could happen with packages due to altitude change.
Yep – altitude has a hand in a lot of those inflated bags but not sure about yours. Good move to return it – better safe than sorry.
I’ve been surprised to learn how common this problem. Nope, don’t attribute the inflated bag in my fridge to altitude.
Yes, seen this before. The cheese did start to ferment inside the bag. Usually happens prior to getting refrigerated it gets hot then the bacteria starts growing thus producing gasses that can’t escape. Always fun to put a knife in them as they do explode! I am sure I wouldn’t do that now as cheese is crazy expensive and I would also return it to the store of purchase. Mostly this happens to me in the states camping as temperatures vary when transporting food from one location to another.
I’m learning a lot via reader comments like yours.