Ask MetaFilter questions tagged with spoilage

Can mold grow on food packed in oil?

aws17576 — Sun, 14 Dec 2008 16:35:18 -0800

Can mold grow on food packed in oil? There's some "Can I eat this?" context here, but I've fairly well decided at this point not to eat the food in question (some roasted bell peppers that I attempted to preserve 6 weeks ago in a refrigerated jar of canola oil), since having read elsewhere that oil-packing will not prevent the growth of botulism unless the packed food is properly dried and/or acidulated.

But can the white spots which recently appeared on those peppers really be mold? If so, then one of two principles I had thought to be true must be upset: that mold requires oxygen to grow, and that submerging food in oil creates a seal which is impermeable to oxygen. On the other hand, if these spots aren't mold, what else might they be? (Sorry, I would provide a photo if I had a working digital camera...)

Finally, the next time a peck of peppers tumbles my way, what might I do differently to preserve them safely? Is there any way to do it that isn't tantamount to pickling them (and thus changing their flavor significantly)?

My rice cooker keeps infecting my rice!

rxrfrx — Wed, 23 Jul 2008 17:26:59 -0800

My Zojirushi rice cooker is contaminated with some kind of bacteria or mold. If I leave cooked rice in it for more than 24 hours, the rice goes mushy and stinky. This never happened with my $15 cooker. Help! I have a made-in-Japan Zojirushi rice cooker (NS-JCC10) that I bought used on Craigslist for $50. Good deal, right? It makes slightly better jasmine rice than my $15 cooker, and way better short grain rice.

Problem: I am used to cooking rice, scooping some out, and then closing the lid (with the cooker unplugged) and coming back over a period of a few days to get the rest of the rice. I've never had my rice spoil in the $15 cooker, which makes sense, because the cooking process sterilizes the inside of the unit with steam.

In the Zoji machine, the rice comes out fine, I scoop out some rice, close the lid, and come back the next day to find some absolutely foul mushy stuff. The rice becomes liquified and slightly blue over the course of a few days. This happens even if I scoop the rice with a spoon that I've sterilized by boiling.

I suspect that the steam vent unit is somehow allowing steam to condense on a cool, non-sterile surface and then drip back into the rice pot. I've pulled out the steam vent plug thingy and soaked that in rubbing alcohol, but there's a lot of space inside the lid that I can't reach (and it smells like the gross stuff that grows on my rice).

Is there some way to disassemble the whole lid and get in there? Has anyone had a similar problem? Thanks!

How long can food be unrefrigerated during a walk home from the grocery store?

mrkohrea — Sun, 28 May 2006 14:11:02 -0800

I have this idea that I want to walk to and from the grocery store to have an excuse to take a long walk (perhaps as long as an hour each way). How long can the walk be before the food becomes unsafe to eat? I assume that refrigerated proteins have the shortest walk time (fish, eggs, chicken, beef). What about frozen foods? In addition to safety, how about taste? For example, I believe that orange juice tastes worse when exposed to heat. How does the outside temperature affect the walk time? Would buying some kind of insulated bag extend the walk time significantly?

If I left my rice out for 12 hours, is it unsafe to eat?

sirion — Sat, 19 Nov 2005 09:27:15 -0800

I made some rice pilaf yesterday morning, ate some, and left it in the pot until I came home at night, when I promptly stuck it in the fridge. Is it safe to eat?

What goes in the fridge and what doesn't?

soyjoy — Fri, 06 Aug 2004 10:52:44 -0800

In your house, what food does, or does not, need to be refrigerated? I say "in your house" because my mom and I were just discussing how some of these decisions seem to be purely based on one's upbringing rather than science. I'm willing to bet there's a good bit of regional/familial variation. Mom noticed my wife and I had ketchup in the fridge, which back when I was growing up I thought ludicrous, but my wife's family kept it there, so we just fell into it. What's the principle by which you definitively determine whether a food needs to be refrigerated after opening? (Stuff like dairy - other than butter - and berries is obvious, right? I'm talking about the borderline stuff.)

Can Butter Go Rancid?

Brad — Wed, 24 Mar 2004 20:33:34 -0800

Once again microbiologists & bacteria enthusiasts your wisdom is needed. My roommate is mad because I left the butter out overnight, he won't touch it and said I have to buy a new stick. But my grandma always kept her butter in a covered dish on the counter, not in the refrigerator. My question then, what are the facts here: does butter require constant refrigeration? How long till butter goes bad {packaged, refrigerated, covered dish} and in what ways, and at what risk?