How Risky Is It to Eat Questionable Leftovers?

meat-thermometer for food safetyOne of the most common questions on cooking sites and forums is whether leftover food should be thrown out. The best advice is to prevent these questions , by learning how to store food properly, estimate quantities, keep track of what you have, and use leftovers creatively.

But what happens if you fear your food has been hanging around for too long? You can look up storage times on various sites, but the recommendations tend to be overly cautious. So much depends on how the food was prepared, and the storage conditions. I suggest using those sites only as a general guideline. If the food looks and smells good, it’s probably safe. And if the food looks or smells off, throw it out even if the guidelines say it’s safe.

If you are new at this and don’t trust your judgment, put the questionable food back in the refrigerator and check it the next day. If you are still in doubt, that means it was fine yesterday. If it really stinks, next time you will not keep it for so long. Do this often enough, and you will gain confidence.

The bacteria that hang around our kitchen are usually not dangerous. But the ones that come into the house from the farm and store, can be. So if you are careful to cook food carefully, handle raw meat as little as possible, and wash your hands, dishes, and counters, you are unlikely to wind up in the hospital with food poisoning.

How risky is it to eat spoiled food? The bacterium Clostridium perfringens is the one most likely to infest cooked meat.

I read several websites on this bug, including the Center for Disease Control. C. perfringens is everywhere, so it quickly colonizes food. Once it multiplies past a certain point, it can cause illness—namely diarrhea with an onset of 6-24 hours after eating the food. The illness generally lasts less than 24 hours.  It is not life-threatening unless you are very young or very old.

I would not wish diarrhea or food poisoning on anyone, nor am I recommending that you eat food that has been questionably stored. 

And note this statement by the CDC:  Foods that have dangerous bacteria in them may not taste, smell, or look different. Any food that has been left out too long may be dangerous to eat, even if it looks okay.

You can definitely get sick from food that looks and tastes fine. However, when food was fully cooked to start with, the chances are low. Food that has been infected by large amounts of bacteria usually smells and looks bad. And I think it’s fair to assume that when food looks and smells fine, any illness you get from common air-borne bacteria will be milder than it would be when the food is obviously spoiled.

If you do unintentionally eat foods containing excess amounts of C. perfringens,  you will probably get diarrhea, and you’ll feel lousy, but you are unlikely to end up in the hospital.  The same applies to the other bacteria floating around your kitchen. The symptoms might be slightly different, but they are still unlikely to make you very sick.

I want to emphasize that the above ONLY applies when the food has been fully cooked. There are some bacteria, like salmonella or E. coli, that you should never play around with. And if you or someone in your household is pregnant, sick, very young, or very old, you will want to be more cautious.

There is a downside to throwing out food that is still good. Wasting food uses up all of the resources used to grow, transport, and cook the food. It creates problems in the environment. For some people, it may put a serious dent in their budget.

What’s the bottom line? Educate yourself and use common sense. Store food wisely and carefully, cook it fully, and use up leftovers quickly. Always examine food before serving. And make the decision that you are most comfortable with.

You may also enjoy:

Is This Food Safe to Eat?

Ten Tips to Cut Your Produce Bill

Evaluating the True Cost of Food

9 Tips to Help Food Last Longer

image: Robert S. Donovan


  1. Nice article, Hannah!

  2. OHgoodness says

    Please for goodness sake admit you were wrong and let it go. .7

  3. Our folks and grandparents did a lot of things that we don’t encourage today. Leaving roasts on the stove for hours after dinner – so we could nibble through the night if we wanted.

    Somehow we survived.

    In developing nations and many European countries egs are not refrigerated. But, then again, they are 1) fresh and 2) eaten within a week.

    Just found you blog.
    I’m your newest follower.

    • Hi Dana,
      Eggs here in Israel aren’t refrigerated either, and have an expiration date of a month after they are laid. I think they are not washed, though, like they are in the US.
      My mom would never have done that with a roast LOL. My grandmother, maybe.
      Thanks for the follow! Going to check out your site now.

  4. Hello “Bacillus cereus”.

    Unfortuneatly there are organisms that produce nasty stuff, that isn’t destroyable with Heat.

    • Hi Han,
      Thanks for your comment.
      Where did you find that it is not destroyed by heat? Anyway, it sounds like a nasty bug but not one that will kill you.