Food storage / spoilage / safety

[pooteeweet]

So. I think it would be nice to have a thread discussing the ins and outs of how to keep your food from going bad, of how to tell if you're unsure of an item's edibility, and of under what circumstances a faulty decision could have severe consequences.

I don't have a specific, pressing question in mind, I just find myself wondering about these things now and then. Does anyone feel like they have any general wisdom to share in these topics? What I'm mainly interested in is the possible discrepancy between reality and the generally approved guidelines. I mean, when I look these things up it seems like the official stance is along the lines of "Food is only good for 1-2 days after you cook it" and "If it's been in your freezer for more than a few months, toss it". But I've definitely eaten stuff that would be considered very questionable by those sorts of standards. Last night I made a casserole using soup from about a week ago (and that soup, in turn, was made with the scraps of a curry from a few days before that). It was amazingly delicious and nobody's gotten sick yet (no meat in any of those leftovers, by the way).

Is anyone knowledgeable about the specifics, variables, and intricacies of food storage timelines, methods, and the different degrees of health-risk involved at any given point? Or just some anecdotal evidence, or semi-educated guesses/opinions?

Other related questions I've had recently:
1) Is the soup I put in my freezer last fall still fair game?
2) Are baby carrots still good up until they start exhibiting obvious signs of spoilage? I mean, sometimes they last for a good, long time in the fridge and they aren't mushy or smelly or anything but you just have to wonder if they're really ok.
3) I read that canned food is only good for 1-2 years. Is that strictly true? I mean, I don't think I let cans sit in my cupboard for that long, but... there goes a good chunk of my how-to-survive-in-case-of-apocalypse plan.
4) Speaking of cans, how commonly are they infected with botulism? I mean, in a hypothetical near-starvation situation, if all you had were 5-year-old cans of food, would you be fairly safe eating them or would you be playing total Russian roulette? And how much of a chance are you taking when you buy discount dented cans?

[Bakemaster]

1) Is the soup I put in my freezer last fall still fair game?
2) Are baby carrots still good up until they start exhibiting obvious signs of spoilage? I mean, sometimes they last for a good, long time in the fridge and they aren't mushy or smelly or anything but you just have to wonder if they're really ok.
3) I read that canned food is only good for 1-2 years. Is that strictly true? I mean, I don't think I let cans sit in my cupboard for that long, but... there goes a good chunk of my how-to-survive-in-case-of-apocalypse plan.
4) Speaking of cans, how commonly are they infected with botulism? I mean, in a hypothetical near-starvation situation, if all you had were 5-year-old cans of food, would you be fairly safe eating them or would you be playing total Russian roulette? And how much of a chance are you taking when you buy discount dented cans?

1) You need to test the temperature of your freezer if you want a good answer for this. Find a thermometer that will record high and low peak temperatures over time, leave it in the freezer to get cold, then quickly turn it on and leave it in the back (in the front, opening the door will throw your readings off a lot more) for an afternoon during hot weather in which you access the freezer (for ice or whatever) a few times. The temperature ideally should not have peaked above 35F/2C; more importantly, when the door has been closed, the thermometer should read 32/0 or below. Food at 33 F feels frozen but is not, and you're not halting spoilage, only slowing it. Generally, I think a year in the freezer is too long for anything if your freezer is a simple one attached to your fridge. Two months is my personal limit for uncooked meats, three or four if cooked, depending on how fresh it was before freezing, and six months for everything else.

2) I think the difference here comes from the fact that sometimes your fridge or crisper drawer is more or less clean, even when there's nothing in it. If something rots in the drawer, and the bag isn't airtight, you should wash the drawer out. If the carrots aren't slimy and don't have brown spots on them, they're fine.

3) http://www.foodreference.com/html/tcann ... flife.html — The highlights are that as long as the can has no dents in it, is not bulging, and hasn't been stored for substantial periods in very warm areas, it'll stay good longer than you'll live to eat it. Sell-by dates are usually around 2 years because flavor does deteriorate and the manufacturers want to make sure they don't get sued in the case of a very unlikely accident.

4) Don't buy dented cans unless you can guarantee the denting was recent (e.g., you bought it undented and it's been in your cabinet for a few weeks—that should be fine). Botulism causes the can to swell up and deform, but not right away, and the food can be unsafe before the shape of the can changes. And the danger isn't necessarily just from cans that were infected before they went on the shelf—bad stuff can potentially get in through a dent, even if the food was sterile to begin with. Always smell the contents of a dented can after opening, and if it's questionable, don't eat it.

[3fj]

And if you trust your immune system, and it doesn't smell/look bad, its probably ok.

At worst, you'll end up with Ebola, but more likely you'll just end up a bit pukey for a few days.

I love being young and reasonably healthy. You get to do so many stupid things with your digestive/urinary systems.

[Grincement]

I have to say that the current guidelines strike me as rather extreme, but of course they are, otherwise you'll be sued.

I use my eyes and nose as first check, and then my tongue. If your meat has a bit of a green look to it, probably not so great. If it tastes off, probably best not to carry on eating it (very hard when on a student budget). Seriously, your body is quite able to cope with a few iffy bits, though if you do have a weaker immune system then maybe a bit more care should be taken.

One thing I'm always aware off is left over rice, as first time cooking doesn't always kill off bacteria and reheating doesn't either...but the chances of there being the killer bacteria, minimal.

DISCLAIMER: Eat food at your own risk, and cook it properly! Do not take my advice, I grew up with a fruit salad my grandmother first made years ago and just continues to top up with fresh fruit, never emptying the bowl. It's gorgeously alcoholic now!

[PatrickRsGhost]

My mom taught me the golden rule about leftovers and other consumables in the fridge: when in doubt, throw it out. If you question how long it's been in there, chances are it's no longer fit for eating.

One lesson I have learned from working in a restaurant where we often prepare parts of the food in advance (dough for pizza crusts, mixing toppings as "shortcuts" for the "specialty" pizzas, etc.) is to date your food. Get some masking tape and a Sharpie, and write on the tape when you put it in the freezer. This way you know when you put the food away, and know when to toss it out. In general, you don't want to leave food in the freezer for more than one year.

Canned goods (tin cans and glass jars) are usually good for about five or six years. Botulism, as others have said, only really occurs if the can becomes dented, or is exposed to warm temperatures over a period of time, and begin to swell up. To help improve your paranoia, botulism can begin at the processing plant where the canned foods are processed. Sometimes they're not sealed properly and air can leak through, causing botulism, mold, and other wonderful microorganisms to set up shop. I remember a couple years or so ago buying a couple of jars of spaghetti sauce, and had to return one of them. The jar's lid looked like it had been nicked by a blade of some sort. My theory was that whoever had opened the box to stock the jars onto the shelves had accidentally hit the jar with their blade while cutting into the box. There was a large blob growing on top of the jar's contents. At first I thought it was a large mushroom that had somehow been squeezed in, and wasn't sliced up, but that didn't seem right. My suspicions were later confirmed when I looked at the label to double-check: the sauce flavor made no mention of mushrooms. I could have taken it back to the store, but what someone later told me, that would have been a bad thing. That would have involved a large recall of every jar of sauce on their shelf, and probably could have caused a major panic. Instead I called the company that produces the sauce, and they sent me a box to ship the jar of sauce back in, as well as a check as a refund for the sauce. I had placed the jar in a Ziploc bag before putting it in the box, just in case it leaked.

One thing I like about home canning my own vegetables or other foods (I have canned spaghetti sauce, chili, and applesauce), is that I know when the food was processed, and if there's any problems with it, I know where the blame can be applied. There's less of a risk of cross-contamination when it comes to home canned foods over canned foods purchased at the store, as long as you do it properly.

One thing you can also do to help prolong the life of your food is to buy one of those vacuum-sealers and store all your food that way. This helps to cut down on the spoilage on a lot of foods, both in the fridge and the freezer.

[Yggdrasil]

At worst, you'll end up with Ebola, but more likely you'll just end up a bit pukey for a few days.

I think you mean E. coli a common bacteria that can sometimes be pathogenic and cause food poisoning (though most strains are fairly harmless and are part of the natural fauna of your digestive tract). Ebola is a deadly virus famous for nearly wiping out entire villages in Africa during the 1970s.

[aro3n]

just wondering, I'm gonna soon pick up sushi from a sushi bar, and I need to transport it via train & walking outside, the sushi would contain raw fish, but they would be kept in their little boxes (i presume they give those for takeout). Would it be able to survive in the train system (~1 hr) and (~30 min) walk to my house? Or should i carry some ice?

[3fj]

At worst, you'll end up with Ebola, but more likely you'll just end up a bit pukey for a few days.

I think you mean E. coli a common bacteria that can sometimes be pathogenic and cause food poisoning (though most strains are fairly harmless and are part of the natural fauna of your digestive tract). Ebola is a deadly virus famous for nearly wiping out entire villages in Africa during the 1970s.

The sentiment is the same, as far as im concerned. "Cook your food, trust your body. If that fails, you can only get [random very nasty disease] if your very unlucky and follow terrible food hygiene"

[PatrickRsGhost]

just wondering, I'm gonna soon pick up sushi from a sushi bar, and I need to transport it via train & walking outside, the sushi would contain raw fish, but they would be kept in their little boxes (i presume they give those for takeout). Would it be able to survive in the train system (~1 hr) and (~30 min) walk to my house? Or should i carry some ice?

Get an insulated lunch bag or small cooler, and a couple of those blue ice packs or blocks that you can stick in the freezer. That should keep it cool for two or three hours. You can probably call ahead and place your order right when you're at a point that it would take you just as long to get there, as it would for the restaurant to prepare it.

[blackrose]

I think that people are too uptight about food safety. I eat stuff with raw egg and I'm still here. I like my meat rare, and I've yet to get sick. I also like the ideas of having antibodies and resistances to several bacterium because I've chosen to "eat dangerously". This recent "salmonella outbreak" was ridiculous. Only 100 or so people got sick off of the peppers. That really doesn't sound like too bad odds when I figure many, many more people than that actually ate the peppers.

But yes, there needs to be a reasonable assurance that food isn't tainted with the plague. If there are large amounts of people getting sick (hundreds) that is a problem. Otherwise, it's just another unnecessary worry and agent of fear.

[3fj]

I think that people are too uptight about food safety. I eat stuff with raw egg and I'm still here. I like my meat rare, and I've yet to get sick. I also like the ideas of having antibodies and resistances to several bacterium because I've chosen to "eat dangerously". This recent "salmonella outbreak" was ridiculous. Only 100 or so people got sick off of the peppers. That really doesn't sound like too bad odds when I figure many, many more people than that actually ate the peppers.

But yes, there needs to be a reasonable assurance that food isn't tainted with the plague. If there are large amounts of people getting sick (hundreds) that is a problem. Otherwise, it's just another unnecessary worry and agent of fear.

But do you eat raw egg that's been sitting there overnight?

Food safety is just as much about the enivroment you keep the food in and the length of time its left there.

[Grincement]

Can anyone explain to me what the little ice symbols of food mean. It seems to range between 1 to 3 of these and they also appear on the draws of our new freezer. I'm curious, is this something about how long they can be frozen for??

[3fj]

European freezers, and refrigerators with a freezer compartment, have a four star rating system to grade freezers.

• * : min temperature = -6°C. Maximum storage time for frozen food is 1 week
• ** : min temperature = -12°C. Maximum storage time for frozen food is 1 month
• *** : min temperature = -18°C. Maximum storage time for frozen food is 3 months
• *(***) : min temperature = -18°C. Maximum storage time for frozen food is up to 12 months

[Bakemaster]

I eat stuff with raw egg and I'm still here.

As 3fj mentioned, it's not just about the current state of the food, but how much you know about the past state of the food. If you just took the egg out from underneath the hen, you could crack it and toss it down right then and there with no worries. I make certain cake frostings with raw egg yolk, and it's wonderful, but I always use eggs from my own fridge so I know when they were purchased and that they've been handled safely since then. In less certain situations, there is greater risk; for healthy teenagers and young adults that may not be significant, but something that would give us a brief spate of the runs might very well kill a young child or elderly person. Since nobody's young forever, and sometimes we're not the only person eating what we cook, it makes sense to develop reasonably cautious habits from the start.

[Coin]

I rummaged in my cupboard for a snack just now and came upon a bag of popcorn; Plain corn which hasn't been popped. The date given on the bag is from the turn of the century (13-03-2000) but the corn smell fine and my brain reasons that since it's dried seeds it should be safe for consumption.
My questions to the fora are as follows: Does anyone know if dried corn goes off? Do you think it would be safe to make popcorn out of 12 year old corn?

[poxic]

Give it a try and see. There has to be some residual moisture in a kernel for it to pop, I think, so if they are too dry they'll just burn.

If they do pop successfully, check the smell and/or taste. No good, no eat.

[PAstrychef]

If there's no insect activity it should be fine. Might taste like crap, but it won't kill you. So go ahead and pop some.

[Coin]

Thanks for the response guys! In the end, I didn't make any last night but I'll see if I can try some today, for science.

[AvatarIII]

Give it a try and see. There has to be some residual moisture in a kernel for it to pop, I think, so if they are too dry they'll just burn.

If they do pop successfully, check the smell and/or taste. No good, no eat.

my guess is that there's probably a percentage of the corn that has to definitely pop for the corn to be considered "good", and over time that percentage decreases, until a time that less than that percentage will definitely pop, and that is what the use by date on popcorn probably is, bacterial or fungal contamination is unlikely when each kernel is dry and sealed, and cooking them would kill off any bacteria or fungal spores on the kernel anyway. I'm actually interested to know what happens but my guess is also that they'll probably be fine, but less will pop than would pop if the corn was fresh,

[mercutio_stencil]

For almost any food you prepare, especially one that's been kept in the fridge, it will look and taste bad long before anything harmful can grow in it.

Most expiration dates are really 'best before' dates, the food might change, and be less appealing, less nutritious, or just less tasty, but it's unlikely to be harmful.

Botulism in canned foods is rare, the FDA is pretty strict about it.

Popcorn has such a low water activity I would find it hard to imagine anything could grow on it, but viability is a different thing. I'm curious to see what happens, and I'll chip in a few dollars towards your hospital bill if you do get ebola.

[Coin]

Argh, I shouldn't have left them on the kitchen counter! Someone threw them away without my knowledge.
Sorry fellow forumites; the experiment has been cancelled

[poxic]

Easy to fix: go buy another bag of popcorn and keep it in the cupboard until 2014.

[Coin]

Well, these were a bit older than that. They were over a decade old...

[AvatarIII]

Argh, I shouldn't have left them on the kitchen counter! Someone threw them away without my knowledge.
Sorry fellow forumites; the experiment has been cancelled

Whoever it was owes you big time!A decade of your life, wasted!! who throws away other people's stuff anyway?
Is there no way to recover the lost sample?

[Coin]

Argh, I shouldn't have left them on the kitchen counter! Someone threw them away without my knowledge.
Sorry fellow forumites; the experiment has been cancelled

Whoever it was owes you big time!A decade of your life, wasted!! who throws away other people's stuff anyway?
Is there no way to recover the lost sample?

Ah, there are greater powers in this world than that of my own. I am staying with my parents over summer and in the kitchen, no greater ruler dwelt than my Mother.

[sardia]

Has anyone read Modernist Cuisine Vol 1.? It has a fascinating three chapters devoted to food storage, freezing food, and spoilage.
Onto the OP's questions:
When one freezes food, it takes time for the soup to cool down until it is in equilibrium with the freezer. During that time, microbes are free to grow on the soup, depending on nutrient availability, PH level, and temperature. As the temperature lowers, growth slows to a crawl, and eventually stops when brought below a critical temperature(depends on species of bacteria). Note in the attached pictures that most bacteria stops dividing below -2 Celsius. Next, consider the water activity, (how much water available for bacteria to use) which isn't a factor since your soup isn't so heavily laden with salt/sugar/chemicals that it is thicker than molasses.
Since I doubt you took the time to bathe your tub of soup in a saltwater ice bath, any bacteria killed by cooking of the soup will be replaced by more bacteria growing as the soup cools in your freezer. FDA regulations says that any meat held at -4 degrees Celsius can be stored indefinitely. I cannot speak as towards it's texture and taste, but it should be fairly safe. As always, consult the charts on how much bacteria have grown, and use your immune system to deal with the rest.

[Bakemaster]

Has anyone read Modernist Cuisine Vol 1.?

I'm just $450 away from a real legible connection.