# Just ate peanut butter with an expiration date of 2003. What will happen? **URL:** \ **Category:** Factual Questions\ **Created:** [April 13, 2010, 11:29am UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937 "2010-04-13T11:29:09Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 13, 2010, 11:29am UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/1 "2010-04-13T11:29:09Z")
That’ll teach me to sneak a bite of someone’s peanut butter out of the company’s fridge. I’m working overtime and am starving, and found a jar of peanut butter in the work fridge. It smelled OK, but the taste was just a little off. Not spoiled, but unusually oily, I guess you could say. So then I took a look at the lid and saw the expiration date was May 2003. So, is there anything interesting that’s going to happen to me and my digestive system in the next 24 hours? ---
**Author:** ![NadaHappyCamper](https://avatars.discourse-cdn.com/v4/letter/n/278dde/32.png) [@NadaHappyCamper](https://boards.straightdope.com/u/NadaHappyCamper)\ **Post date:** [April 13, 2010, 11:54am UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/2 "2010-04-13T11:54:57Z")
How are you feeling now?Proablly nothing, just in case Bye. ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 13, 2010, 12:04pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/3 "2010-04-13T12:04:41Z")
It’s been 45 minutes and nothing to show for it except some exceptionally pungent burps. ---
**Author:** ![Hypnagogic\_Jerk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hypnagogic_jerk/32/4252_2.png) [@Hypnagogic\_Jerk](https://boards.straightdope.com/u/Hypnagogic_Jerk)\ **Post date:** [April 13, 2010, 12:21pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/4 "2010-04-13T12:21:14Z")
Keep us posted, I want to see how this develops. There’s a GQ that will answer itself! ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [April 13, 2010, 12:32pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/5 "2010-04-13T12:32:56Z")
The off taste of old PB is most likely just rancid change in the fats, resulting in breakdown products (aldehydes and ketones) which may taste/smell unusual but should be no danger. ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 13, 2010, 12:34pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/6 "2010-04-13T12:34:29Z")
At this point feeelinga’ tad lightaytheadeeedd but tahytyaahts a’ll;; did I maeentyion thearRE WASa qfunmny kineaD OF fuingus iiii notiicved in the4 jar lataaater /a/??? ---
**Author:** ![Mr.Excellent](https://avatars.discourse-cdn.com/v4/letter/m/f19dbf/32.png) [@Mr.Excellent](https://boards.straightdope.com/u/Mr.Excellent)\ **Post date:** [April 13, 2010, 1:33pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/7 "2010-04-13T13:33:57Z")
Have a good trip. 🙂 ---
**Author:** ![BlinkingDuck](https://avatars.discourse-cdn.com/v4/letter/b/eada6e/32.png) [@BlinkingDuck](https://boards.straightdope.com/u/BlinkingDuck)\ **Post date:** [April 13, 2010, 1:36pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/8 "2010-04-13T13:36:49Z")
Use the codeword ‘beagleboy’ when contacted via seance so we know it is really you. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [April 13, 2010, 1:46pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/9 "2010-04-13T13:46:59Z")
The main concern would be oxidation - rancidity, which you’ve already noticed. There’s a slight chance of mold spoilage, but peanut butter manufacturers have to be pretty paranoid about keeping their product mold-free, because the peanuts can grow some pretty dangerous molds. ---
**Author:** ![Hypnagogic\_Jerk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hypnagogic_jerk/32/4252_2.png) [@Hypnagogic\_Jerk](https://boards.straightdope.com/u/Hypnagogic_Jerk)\ **Post date:** [April 13, 2010, 1:59pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/10 "2010-04-13T13:59:24Z")
> [@Koxinga](#): > > At this point feeelinga’ tad lightaytheadeeedd but tahytyaahts a’ll;; did I maeentyion thearRE WASa qfunmny kineaD OF fuingus iiii notiicved in the4 jar lataaater /a/??? Shoehorn butterhorse? ---
**Author:** ![Snowboarder\_Bo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowboarder_bo/32/229_2.png) [@Snowboarder\_Bo](https://boards.straightdope.com/u/Snowboarder_Bo)\ **Post date:** [April 13, 2010, 2:03pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/11 "2010-04-13T14:03:49Z")
> [@Hypnagogic\_Jerk](#): > > Shoehorn butterhorse? Purple monkey dishwasher. ---
**Author:** ![Rafe\_Hollister](https://avatars.discourse-cdn.com/v4/letter/r/fbc32d/32.png) [@Rafe\_Hollister](https://boards.straightdope.com/u/Rafe_Hollister)\ **Post date:** [April 13, 2010, 2:31pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/12 "2010-04-13T14:31:15Z")
> [@Snowboarder\_Bo](#): > > Purple monkey dishwasher. LOL I use this phrase all the time and thought I was the only one. 😃 ---
**Author:** ![WorkInProgress](https://avatars.discourse-cdn.com/v4/letter/w/f04885/32.png) [@WorkInProgress](https://boards.straightdope.com/u/WorkInProgress)\ **Post date:** [April 13, 2010, 2:44pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/13 "2010-04-13T14:44:51Z")
Make sure it was not recalled for salmonella. ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [April 13, 2010, 2:46pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/14 "2010-04-13T14:46:07Z")
> [@Koxinga](#): > > At this point feeelinga’ tad lightaytheadeeedd but tahytyaahts a’ll;; did I maeentyion thearRE WASa qfunmny kineaD OF fuingus iiii notiicved in the4 jar lataaater /a/??? Dude ----- stop bogarting that jar and give me a hit! 😉 ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 13, 2010, 2:49pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/15 "2010-04-13T14:49:50Z")
Guess I survived. The walls are still kind of . . . moving, but not moving, you know? . . . but no upchucking or diahrrea, so I guess I don’t have botulism, anyway – thanks for the replies. BTW, what kind of dangerous molds grow on peanuts? ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [April 13, 2010, 2:52pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/16 "2010-04-13T14:52:57Z")
> [@WorkInProgress](#): > > Make sure it was not recalled for salmonella. Except that after 7+ years I would expect there to be little left other than _Salmonella spp_. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [April 13, 2010, 4:39pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/17 "2010-04-13T16:39:05Z")
> [@Koxinga](#): > > Guess I survived. The walls are still kind of . . . moving, but not moving, you know? . . . but no upchucking or diahrrea, so I guess I don’t have botulism, anyway – thanks for the replies. > > BTW, what kind of dangerous molds grow on peanuts? [Aspergillus molds grow on peanuts, and produce aflatoxin.](http://en.wikipedia.org/wiki/Aflatoxin) ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 13, 2010, 4:44pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/18 "2010-04-13T16:44:35Z")
> [@Nametag](#): > > [Aspergillus molds grow on peanuts, and produce aflatoxin.](http://en.wikipedia.org/wiki/Aflatoxin) Holy shit, do I need to worry about this now? ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [April 13, 2010, 4:51pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/19 "2010-04-13T16:51:10Z")
> [@Koxinga](#): > > Holy shit, do I need to worry about this now? Hey, you want to die ignorant? 🙂 Tris ---
**Author:** ![Snickers](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@Snickers](https://boards.straightdope.com/u/Snickers)\ **Post date:** [April 13, 2010, 4:53pm UTC](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937/20 "2010-04-13T16:53:36Z")
> [@Snowboarder\_Bo](#): > > Purple monkey dishwasher. I prefer “scooter my daisyheads.” [Next page](https://boards.straightdope.com/t/just-ate-peanut-butter-with-an-expiration-date-of-2003-what-will-happen/535937.md?page=2)