PB and food safety and raisin toast!

March 28, 2011 11:04 PM

"Should I eat this?"-filter. Left a jar of peanut butter open on my counter and went out of town for 5 days. The house usually stays pretty cool. Safe to eat?
posted by liketitanic to food & drink (33 answers total)

With gusto!
posted by barnone at 11:05 PM on March 28, 2011 [1 favorite]

Absolutely. I don't even bother to refrigerate peanut butter.
posted by Gilbert at 11:05 PM on March 28, 2011 [3 favorites]

I leave jars of peanut butter in my pantry for months at a time, never had any problem with spoilage. I don't think I've even had a jar smell the least bit rancid.
posted by TungstenChef at 11:06 PM on March 28, 2011

Even though there was no lid on the jar?
posted by liketitanic at 11:07 PM on March 28, 2011

If it would make you feel better, maybe scrape the very top layer off to rid it of dust and other nasties? It's not as if an opened-but-lidded peanut butter jar exists in a vacuum, anyway.
posted by charmcityblues at 11:08 PM on March 28, 2011 [1 favorite]

Coming in to say what charmcityblues just did.

The lid is keeping out dust and bugs, and that's about it.
posted by bardophile at 11:20 PM on March 28, 2011

Scrape the top quarter inch off in case you had flies landing on it or mice hawking loogies into it or whatever, but yeah, you're fine.
posted by infinitywaltz at 11:22 PM on March 28, 2011

It might help to note whether you are using natural PB or one with all the preservatives.
posted by acoutu at 11:36 PM on March 28, 2011

According to StillTasty, peanut butter, commercially manufactured and processed (containing hydrogenated fat or other stabilizers) — opened jar, can be kept in the pantry for at least three months unless it "develops an off odor, flavor or appearance." It shouldn't matter that you left the lid off.
posted by grouse at 12:18 AM on March 29, 2011 [1 favorite]

I grew up in a house where the peanut butter was never refrigerated, and I never died, not even once.
posted by lekvar at 12:19 AM on March 29, 2011 [5 favorites]

Totally fine- eat it!
posted by emd3737 at 12:27 AM on March 29, 2011

I am assuming that this is the sweet kind of peanut butter, yeah? Then you should be totally fine. If it's that 100% style stuff, I would not eat it. I think rancid peanut butter gives off a pretty pungent warning odor.
posted by molecicco at 12:49 AM on March 29, 2011

Is there anything growing on it? No? Then nom nom nom! (And I am the [drama] Queen of Don't eat that, you'll die.)

However, physical health aside, I believe because of your question and follow up, your mental health will be negatively affected by eating this - you will worry for weeks! as to whether every physical symptom is related to the peanut butter, whether you will get cancer. This is where we need to look into opportunity cost - how much time will you waste on thinking you're dying as a result of eating the PB vs how much did the actual PB cost and could you replace it for what you're worth at your current job X the amount of time you've wasted worrying?


In which case, toss it and start over.
Nice fresh bread is good by itself. I quite like lavishly buttered bread with tinned corn or if you have no butter, pretend you are an English shepherd in an Enid Blyton book, and have a cheese and onion sandwich without butter. (And trivia: my boss is related somehow to Enid, and one of her nephews named Enid Blyton in her honour. How cool is that? Unfortunately none of that family currently writes children's stories)
posted by b33j at 1:10 AM on March 29, 2011

Eat it!
posted by at the crossroads at 1:42 AM on March 29, 2011

Would you eat whole peanuts that had been left uncovered on the counter for 5 days? I'd say it's pretty much the same thing.
posted by esmerelda_jenkins at 3:06 AM on March 29, 2011

It's OK with me if you eat it. Of course, it could kill you, but it's OK with me! JK.

Why is it that no self-respecting microbe will attack this stuff? I've wondered for years why this stuff is the natural equivalent of Velveeta, which is apparently some kind of plastic-based cheese material. I have NEVER put PB in the fridge unless it was natural and prone to separation, and am a) still alive and b) never got PB-based illness. It is just inert or is it antibiotic? WTF? WT PB F?
posted by FauxScot at 3:59 AM on March 29, 2011 [1 favorite]

The low moisture and high fat content of peanut butter keep microbes from being able to live and grow in it. It takes about a year for the oils in peanut butter to go rancid, at room temperature, but that's not a microbial process.
posted by Ery at 5:14 AM on March 29, 2011

Yeah, I didn't think anyone refrigerated peanut butter.

But with the lid off, who knows what kinds of spores and whanot have fallen into it? Wasn't that the first thing us humans learned about microbiology was that uncovered stuff spoiled faster than covered stuff?

If it was me, I would scrape the top layer off and eat it. But I would probably also be leery about it and throw it away before I finished it.
posted by gjc at 6:07 AM on March 29, 2011 [1 favorite]

I'd totally eat it.

But here's the counterargument: a jar of peanut butter costs a couple bucks and can be found at any grocery store. Unless you're seriously broke or seriously hungry, why take the chance?
posted by box at 6:15 AM on March 29, 2011

Scrape off the very top bit in case of dust and eat it. Peanut butter doesn't need to be refrigerated ever, really, the only reason some people refrigerate the all-natural stuff is because it keeps the oil from separating and you having to remix it.
posted by wending my way at 8:19 AM on March 29, 2011

But with the lid off, who knows what kinds of spores and whanot have fallen into it?

The same kind that have fallen on your plates, your napkins, your dish towel, your face, your dog and your kids and your wife and everything else you come in contact with on a daily basis.

Wasn't that the first thing us humans learned about microbiology was that uncovered stuff spoiled faster than covered stuff?

Covering things can reduce exposure to oxygen, which can cause spoilage in some substances (but not peanut butter, except over very long periods of time), and can reduce exposure to microbes or mold which would grow in hospitable environments (which peanut butter is not).

Not all stuff is the same stuff.
posted by ook at 8:21 AM on March 29, 2011

Yes. PB doesn't spoil, and you weren't home, so not much dust got kicked up. No big deal. I dropped a bunch of pb on the floor - it detached itself from the apple slices and glommed onto the floor. So I gave it to the dog, and he's fine. Of course, he eats unspeakable stuff and is fine. Sorry for sharing.
posted by theora55 at 8:29 AM on March 29, 2011

In my home, mice-hocked loogies would be a legitimate worry. Otherwise, yeah, eat it.
posted by MrMoonPie at 8:41 AM on March 29, 2011

My husband lived for a year or two in a commune, back in the early seventies, up on an island in the San Juans. I used to picture it through a fairly misty pair of rose colored glasses as a lovely idyllic place where they had fresh eggs everyday, lived a natural life, and all worked together, and had free love and happiness without having to worry about fatal STDs.

I didn't appreciate the reality of it until I saw an old newspaper clipping about the place. Then we got to talking about it. That 2 story house they lived in? What a shack. Refrigeration? Not a chance. Running water? Run to the creek to fetch it. Electricity? None. A candle eventually burned the place down (but that's another story, and nobody can prove anything anyway). Goats and chickens? Yeah, sure, but they come with manure, and really, who wants to clean that up? Oh, and money? No one had a job, so it was in pretty short supply. But that was ok, because they didn't have to pay for haircuts, after all.

Grocery shopping was a near thing, I guess, because when someone made a major investment in a 5-gallon tub of peanut butter it was a happy day. Protein, fat and deliciousness all ground up into one beautiful giant tub. And it gave meaning and delight to home-baked bread. Mmmm peanut butter.

Until the goat wandered in from the manure covered yard and stepped in it.

Apparently the peanut butter was precious enough that no one wanted to throw it out. The thinking seems to have gone something like, "Well, she stepped into the middle of the tub, right? So the edges should be fine." And everybody took his peanut butter from the edges....for weeks....until the whole thing was gone.

So yeah, go ahead and enjoy your peanut butter. You should be fine.
posted by SLC Mom at 8:50 AM on March 29, 2011 [9 favorites]

Are you absolutely certain your house is free from rodents? The PB is probably fine rancid-wise and if you're not worried about dust particles. But when I was a kid, we briefly lived in a rented place in the country which had mice. We left a jar of peanut butter open on the table overnight and in the morning when I spread some on my toast there was mouse hair in it. Bleck.

I'm guessing cock-a-roaches would probably have taken some nibbles if you've got any of those lurking about.

I wouldn't eat it, personally. But I tend to be more cautious than most.
posted by Serene Empress Dork at 9:07 AM on March 29, 2011

IMPORTANT UPDATE: Ate it.

But here's the counterargument: a jar of peanut butter costs a couple bucks and can be found at any grocery store. Unless you're seriously broke or seriously hungry, why take the chance?

Well, there was only a little left and I didn't think to buy more at the grocery last night and I just got back into town and . . . well, you know.
posted by liketitanic at 9:07 AM on March 29, 2011 [1 favorite]

What? I've never heard of refrigerating peanut butter. How do you spread it?

Well, I learned something new today.
posted by Knowyournuts at 10:14 AM on March 29, 2011

Knowyournuts: eponysterical!

Also, my parents insist on keeping their peanut butter in the fridge. It does indeed make it impossible to spread, causing great big holes in the bread that allow jelly to leak out.

Now that I live on my own, I take great pleasure in room temperature peanut butter. So smooth, so spreadable, so easy!
posted by charmcityblues at 10:23 AM on March 29, 2011

I'm totally a paranoid food-safety nut and even I would eat it without much thought.
posted by rachaelfaith at 10:53 AM on March 29, 2011

Mice are awfully fond of peanut butter, so yeah, scrape the top layer off just in case any visited the jar while you were gone.
posted by exphysicist345 at 12:04 PM on March 29, 2011

Peanut butter DOES spoil if left unrefrigerated. Skippy and Jif are examples of substances that are not peanut butter, but hydrogenated oils mixed with peanuts. Real peanut butter contains just peanuts, and sometimes salt. Nothing else.

Peanut butter tends to go rancid if left unrefrigerated for a while, but I'm sure it's safe to eat if left covered unrefrigerated for a few days. But I have very little regard for food safety, I'm the Evel Knievel of eating.
posted by santaliqueur at 1:40 PM on March 29, 2011

I recently interviewed the research director of a major cancer institute about preventable causes of cancer. Mould on legumes is a cause. I suspect your Skippy or Jif are okay, but I would be worried about natural PB. I would guess it's okay for a few days, but i'm not sure.
posted by acoutu at 10:38 PM on March 29, 2011

IMPORTANT UPDATE: Still alive.
posted by liketitanic at 2:06 PM on March 30, 2011 [8 favorites]