Puffy bag of nuts in freezer
November 27, 2014 8:36 PM Subscribe
I was trying to make a recipe that required pecans today, but when I went to get a bag of pecans from my freezer door, I found that the bag was strangely puffed up, as if someone had inflated it. The bag had never been opened and did not look like this when I originally put it in the freezer after purchase some months ago. Two questions: 1) What could have caused this? (Can things like botulism happen to nuts in a freezer?) 2) Would you still eat the pecans? They looked and smelled 100% normal.
Botulism doesn't puff things up, so that's not your worry (also, while the Botulism spores can totally survive in a freezer, they only activate and produce toxins in warm and anaerobic conditions.)
If things puff up in the fridge, I'd guess fermentation and through them out. But in the freezer -- seems unlikely. Is the bag airtight? If so, my guess is that this is caused by the gas inside the bag and isn't anything to worry about.
(I can't quite figure out why there would be a pressure differential between the inside and outside of the bag, but my guess would be that it involves water vapor somehow.)
posted by goingonit at 8:50 PM on November 27, 2014
If things puff up in the fridge, I'd guess fermentation and through them out. But in the freezer -- seems unlikely. Is the bag airtight? If so, my guess is that this is caused by the gas inside the bag and isn't anything to worry about.
(I can't quite figure out why there would be a pressure differential between the inside and outside of the bag, but my guess would be that it involves water vapor somehow.)
posted by goingonit at 8:50 PM on November 27, 2014
I don't know why your bag puffed up, but air shrinks as it gets colder, it doesn't expand.
It's probably ok, but I'm super paranoid about any food that swell up. I would totally eat a turkey that sat in a car for 4+ hours in November, but I would throw the nuts out. I believe this is a statement about my irrational out of proportion reaction to swollen food packaging and not a statement about the safety of food contained therein.
posted by If only I had a penguin... at 9:17 PM on November 27, 2014 [3 favorites]
It's probably ok, but I'm super paranoid about any food that swell up. I would totally eat a turkey that sat in a car for 4+ hours in November, but I would throw the nuts out. I believe this is a statement about my irrational out of proportion reaction to swollen food packaging and not a statement about the safety of food contained therein.
posted by If only I had a penguin... at 9:17 PM on November 27, 2014 [3 favorites]
I would eat them.
posted by harrietthespy at 9:45 PM on November 27, 2014 [2 favorites]
posted by harrietthespy at 9:45 PM on November 27, 2014 [2 favorites]
Best answer: Actually, having thought it over further, another thing I might do if I couldn't bring myself to throw them out because deep down I know my fear of swollen packaging is irrational: I would put them back in the fridge to be consumed at some later date, after I've forgotten the former swelling of the bag. Then I can eat them without terror.
posted by If only I had a penguin... at 9:53 PM on November 27, 2014 [7 favorites]
posted by If only I had a penguin... at 9:53 PM on November 27, 2014 [7 favorites]
Are they packed in that weird air permeable plastic some produce comes in? I've noticed that puffs up in the freezer sometimes. I don't think you're supposed to freeze stuff in it.
posted by fshgrl at 10:18 PM on November 27, 2014
posted by fshgrl at 10:18 PM on November 27, 2014
Do you usually keep pecans in the freezer? Has this happened before?
Is it possible that your power has failed at some point and you didn't notice? What does other food in your freezer look like?
I am usually on the "eat it" side of this kind of question, but this time I would say toss it, or at least be prepared for funny stuff to happen to your gastrointestinal system: *something* has been producing a gas inside the bag.
posted by Dr Dracator at 12:08 AM on November 28, 2014
Is it possible that your power has failed at some point and you didn't notice? What does other food in your freezer look like?
I am usually on the "eat it" side of this kind of question, but this time I would say toss it, or at least be prepared for funny stuff to happen to your gastrointestinal system: *something* has been producing a gas inside the bag.
posted by Dr Dracator at 12:08 AM on November 28, 2014
Did a bit of googling to see if any of the inert gases used to package food expand when chilled. Didn't come up with anything, but did find this --- apparently 0 to -10 degrees Celcius is the ideal temperature for keeping pecans, andthey should last for 10 to 18 months when kept at that temp. I'd say you're fine.
posted by Diablevert at 2:33 AM on November 28, 2014 [1 favorite]
posted by Diablevert at 2:33 AM on November 28, 2014 [1 favorite]
There might've been some out-gassing from the nuts, perhaps?
I'd eat them.
posted by Sunburnt at 7:20 AM on November 28, 2014 [1 favorite]
I'd eat them.
posted by Sunburnt at 7:20 AM on November 28, 2014 [1 favorite]
I've had this happen with bagged nuts in the freezer. I've used them with no ill effects - I think you're fine.
posted by summerstorm at 8:27 AM on November 28, 2014 [2 favorites]
posted by summerstorm at 8:27 AM on November 28, 2014 [2 favorites]
No gases expand when chilled, inert or otherwise.
However, I've had this happen before, to all sorts of foods that were apparently unchanged. My best guess (and it's a total WAG) is that the plastic tends to want to straighten out as it stiffens in the cold. Thus, it "unfolds" a bit, and since bags aren't always longterm airtight (and perhaps less so at cold temperatures), air gets sucked in to allow the bag to form this shape.
Total WAG, trying to explain what I've seen. Maybe I need to freeze some marbles, or nothing at all, in a baggie and see...
posted by IAmBroom at 9:19 AM on November 28, 2014 [4 favorites]
However, I've had this happen before, to all sorts of foods that were apparently unchanged. My best guess (and it's a total WAG) is that the plastic tends to want to straighten out as it stiffens in the cold. Thus, it "unfolds" a bit, and since bags aren't always longterm airtight (and perhaps less so at cold temperatures), air gets sucked in to allow the bag to form this shape.
Total WAG, trying to explain what I've seen. Maybe I need to freeze some marbles, or nothing at all, in a baggie and see...
posted by IAmBroom at 9:19 AM on November 28, 2014 [4 favorites]
Just chiming in to say that I've occasionally had baggies puff up in a -70 C lab freezer (much colder than a home freezer). The contents have always been fine based on the lab assays we ran, and I've never figured out why it happened. I'll be watching this thread for clues! I'd eat those pecans, but I'm far more cavalier about food safety than most MeFites.
posted by Quietgal at 9:32 AM on November 28, 2014 [1 favorite]
posted by Quietgal at 9:32 AM on November 28, 2014 [1 favorite]
Response by poster: Lol, If I only had a penguin... - that's exactly what I've ended up doing. Although it seems that the pecans are indeed safe - my mom thought I was silly for worrying and ate one, and has suffered no ill effects 18 hrs later. But if anyone has any other ideas as to what might have caused the puffiness, I'd still love to hear them!
posted by st elmo's fire at 10:17 AM on November 28, 2014
posted by st elmo's fire at 10:17 AM on November 28, 2014
However, I've had this happen before, to all sorts of foods that were apparently unchanged. My best guess (and it's a total WAG) is that the plastic tends to want to straighten out as it stiffens in the cold. Thus, it "unfolds" a bit, and since bags aren't always longterm airtight (and perhaps less so at cold temperatures), air gets sucked in to allow the bag to form this shape.However, I've had this happen before, to all sorts of foods that were apparently unchanged. My best guess (and it's a total WAG) is that the plastic tends to want to straighten out as it stiffens in the cold. Thus, it "unfolds" a bit, and since bags aren't always longterm airtight (and perhaps less so at cold temperatures), air gets sucked in to allow the bag to form this shape.
I think that's a very good guess, and I'd like to propose a slight variation of it.
When you open the door of a freezer you generate a slight, momentary vacuum inside it, and when you close it you generate a momentary pressure pulse.
If the closure of a bag just happens to be arranged so as to offer more resistance to gas escaping the bag than entering it -- the opposite of the valve built into some coffee bags, for example -- over time, the sum of all those brief pressure pulses will tend to inflate the bag.
posted by jamjam at 11:18 AM on November 28, 2014
I think that's a very good guess, and I'd like to propose a slight variation of it.
When you open the door of a freezer you generate a slight, momentary vacuum inside it, and when you close it you generate a momentary pressure pulse.
If the closure of a bag just happens to be arranged so as to offer more resistance to gas escaping the bag than entering it -- the opposite of the valve built into some coffee bags, for example -- over time, the sum of all those brief pressure pulses will tend to inflate the bag.
posted by jamjam at 11:18 AM on November 28, 2014
Goddammit, jamjam, I was all prepared to SCIENCE this thing, and now I have to deal with two hard-to-isolate hypotheses.
posted by IAmBroom at 3:53 PM on November 28, 2014 [3 favorites]
posted by IAmBroom at 3:53 PM on November 28, 2014 [3 favorites]
This thread is closed to new comments.
posted by easily confused at 8:49 PM on November 27, 2014 [1 favorite]