# How dangerous is day-old, unrefrigerated pizza? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [November 8, 2010, 5:08pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927 "2010-11-08T17:08:25Z")\ **Posts on this page:** 16\ **Page:** 3
**Author:** ![River\_Hippie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/river_hippie/32/26_2.png) [@River\_Hippie](https://boards.straightdope.com/u/River_Hippie)\ **Post date:** [November 8, 2010, 11:44pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/41 "2010-11-08T23:44:17Z")
I woud eat any or all slices and not think twice. ---
**Author:** ![norinew](https://avatars.discourse-cdn.com/v4/letter/n/eb9ed0/32.png) [@norinew](https://boards.straightdope.com/u/norinew)\ **Post date:** [November 8, 2010, 11:47pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/42 "2010-11-08T23:47:36Z")
> [@EmAnJ](#): > > For some reason, I’ve had it in my head that anything with a tomato base must be refrigerated or it’ll go bad. As others have said, this just isn’t true. In fact, the reason marinara sauce is called ‘marinara’ is that it was discovered centuries ago that it was so acidic that barrels of it could go on sailing ships headed for long voyages, and not go bad. My sister is almost _phobic_ about things being properly and promptly put away (me? I figure, God gave me an immune system, I might as well use it), but the one thing she _will_ eat that hasn’t been thoroughly wrapped and refrigerated is pizza. As long as it’s well-covered, it should be fine the next day. Like others, I’d be wary of toppings like chicken or seafood. But cured meats, cheese, tomato sauce should all be fine. ---
**Author:** ![Smapti](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smapti/32/17938_2.png) [@Smapti](https://boards.straightdope.com/u/Smapti)\ **Post date:** [November 9, 2010, 12:00am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/43 "2010-11-09T00:00:38Z")
From the perspective of a restaurant industry professional, I wouldn’t recommend eating pizza that had been left out overnight. The meat on a pizza is potentially hazardous, and if it has cooked vegetables on it they’re potentially hazardous as well. It only takes 4 hours at room temperature for bacteria present on the food to multiply to potentially hazardous levels - even more so if an inattentive pizza cook didn’t cook the pie long enough to kill the bacteria present in the raw food. That being said, I always stick my leftover pizza in the fridge when i’m done eating what I want to eat right away. ---
**Author:** ![kidneyfailure](https://avatars.discourse-cdn.com/v4/letter/k/9f8e36/32.png) [@kidneyfailure](https://boards.straightdope.com/u/kidneyfailure)\ **Post date:** [November 9, 2010, 12:22am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/44 "2010-11-09T00:22:46Z")
> [@AClockworkMelon](#): > > Are you kidding me? What you’re describing is the best kind of pizza! Seriously! It’s totally safe and totally delicious. ---
**Author:** ![etv78](https://avatars.discourse-cdn.com/v4/letter/e/d78d45/32.png) [@etv78](https://boards.straightdope.com/u/etv78)\ **Post date:** [November 9, 2010, 12:35am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/45 "2010-11-09T00:35:11Z")
As a kid, we’d leave left over pizza in the (cold) oven, in the box. I nuked anything with toppings, but cold leftover cheese pizza is excellent! ---
**Author:** ![EmAnJ](https://avatars.discourse-cdn.com/v4/letter/e/d2c977/32.png) [@EmAnJ](https://boards.straightdope.com/u/EmAnJ)\ **Post date:** [November 9, 2010, 2:13am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/46 "2010-11-09T02:13:53Z")
> [@Colibri](#): > > Most restaurants leave ketchup bottles on their tables without refrigeration and have no problems. A lot of tomato-based sauces are probably acid enough to inhibit bacterial growth. Very good point (et all)! I’m going to leave my next pizza out for a night and try it the next morning. Too many of you attesting to it’s deliciousness has convinced me. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 9, 2010, 2:33am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/47 "2010-11-09T02:33:28Z")
Actually there was a thread on this very subject where the question was is pizza safe after _four hours_? I can’t be arsed to search for it right now, but the consensus was: 4 hour old pizza is teh poison. Which I found absurd, not just because I eat much older pizza all the time but because many buffets and cafes have similar things (e.g. cheesy croissant) that they may leave at room temperature for longer than that. Or maybe there are a lot of places that should be closed down… My WAG is that it may have to do with moisture. That a fairly dry pizza will be fine for, say, 8 hours, but a hypothetical sloppy pizza could become putrid within that time. ---
**Author:** ![Pai325](https://avatars.discourse-cdn.com/v4/letter/p/c68b51/32.png) [@Pai325](https://boards.straightdope.com/u/Pai325)\ **Post date:** [November 9, 2010, 3:12am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/48 "2010-11-09T03:12:37Z")
It’s probably not something I’d recommend, but it hasn’t killed me. I heat it up because I don’t like cold pizza. Whether that kills the bugs or encourages them to multiply faster I don’t know. ---
**Author:** ![Spud](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spud/32/347_2.png) [@Spud](https://boards.straightdope.com/u/Spud)\ **Post date:** [November 9, 2010, 4:41am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/49 "2010-11-09T04:41:08Z")
Apparently the OP didn’t go to college. ---
**Author:** ![Hilarity\_N.Suze](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hilarity_n.suze/32/6223_2.png) [@Hilarity\_N.Suze](https://boards.straightdope.com/u/Hilarity_N.Suze)\ **Post date:** [November 9, 2010, 4:43am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/50 "2010-11-09T04:43:48Z")
I would probably eat them, except for the chicken. Many’s the time I’ve had leftover pizza for breakfast. I’m kind of a picky eater but I’m pretty much immune from food fears. But then, I once ate a caramel that I’d left in my pocket for a wash cycle (and dry cycle). I basically had to gnaw it out of the seam in the lining. I doubt that anyone else would have eaten it. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [November 9, 2010, 5:33am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/51 "2010-11-09T05:33:45Z")
> [@Hari\_Seldon](#): > > I might hesitate over the chicken, but the rest wouldn’t bother me. > > My wife lived for a year with a family in Paris that didn’t have a fridge. They never hesitated to eat left-overs. My grandparents would always keep leftovers in the oven–usually from breakfast. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [November 9, 2010, 6:17am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/52 "2010-11-09T06:17:32Z")
> [@Smapti](#): > > From the perspective of a restaurant industry professional, I wouldn’t recommend eating pizza that had been left out overnight. The meat on a pizza is potentially hazardous, and if it has cooked vegetables on it they’re potentially hazardous as well. It only takes 4 hours at room temperature for bacteria present on the food to multiply to potentially hazardous levels - even more so if an inattentive pizza cook didn’t cook the pie long enough to kill the bacteria present in the raw food. > > That being said, I always stick my leftover pizza in the fridge when i’m done eating what I want to eat right away. This is probably where my questioning came from. It’s been years since I worked in food service, but I remember being very careful with leaving things out. Plain cheese and veggie-topped pies I would have thought would be fine. What gave me pause was the thought of eating meat that has sat out for more than a couple hours. Unrefrigerated meat? Why, next you’ll be trying to get me to eat salted, cured pork products! Oh. So, pepperoni can be cooked, then slowly cooled on a countertop for hours, and there will be little to no (additional) bacteria growing on it? No more than would be on a stick of pepperoni that sits on the counter? But sausage? Dried meats are one thing, but don’t sausages have to be kept refrigerated to retard bacterial growth? Meatballs? ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [November 9, 2010, 6:38am UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/53 "2010-11-09T06:38:03Z")
Eh, I can’t say that any of this pizza is _safe_ to eat. That said, I’ve been in that situation several times. Every time I ate the pizza. Probably luck, but I never got sick. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [November 9, 2010, 12:22pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/54 "2010-11-09T12:22:27Z")
Of course, they’re now almost 30 hours old. Come on, EAT THEM! ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [November 9, 2010, 3:50pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/55 "2010-11-09T15:50:11Z")
> [@amarinth](#): > > Hasn’t killed me yet. > > I do microwave it, because I can’t stand cold pizza - so maybe that takes care of the germs. Might kill the germs, but it wouldn’t neutralize any toxins they might have produced. Having said that, yes, I’ve eaten plenty of leftover pizza in my life and wouldn’t hesitate to eat day-old pizza. Although maybe not the one with chicken. ---
**Author:** ![Rhiannon8404](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rhiannon8404/32/17929_2.png) [@Rhiannon8404](https://boards.straightdope.com/u/Rhiannon8404)\ **Post date:** [November 9, 2010, 4:15pm UTC](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927/56 "2010-11-09T16:15:03Z")
I don’t think I have ever refrigerated left over pizza. We usually stick it in the oven over night, but that is to keep the cats from eating the cheese off. Sometimes I wrap the left over slices in foil so the Kid and **Suburban Plankton** can grab the in the morning and take them to school or work for lunch. [Previous page](https://boards.straightdope.com/t/how-dangerous-is-day-old-unrefrigerated-pizza/559927.md?page=2)