If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?
When in Doubt, Throw it Out!
You cannot always see or smell bacterial contamination. Mold that appears to be growing only on the surface may grow invisible roots into softer foods. Do not rely on a visual inspection or "smell test" to tell you whether or not a food is safe. It's not worth the risk - food poisoning can be much, much worse than an upset stomach.
The Danger Zone
Why does cooking not completely "reset the clock"?
What can I leave out longer?
For foods that aren't potentially hazardous as described above, there's no solid rule, but things are generally safe for much longer than the 2 hours given above. For example, things which are sold at room temperature (e.g. fresh produce, bread, or cookies) are most likely safe at least all day or overnight if not for days or even months. You can find guidelines for common things at StillTasty.
Regulation and Risks
Follow the guidelines set out by reputable regulatory agencies, especially when serving others. Local organizations include:
Other regulatory sources apply in other parts of the word, but major food safety organizations usually agree in essence (if not in complete detail) on most issues.
Failure to follow reputable guidelines is irresponsible if you are serving guests, and failure to follow your specific local codes is likely to be illegal if you are serving customers.
Health codes tend to be very conservative, to fully protect the community. You have the right to take risks on yourself by ignoring their recommendations, but please do not risk the safety of others.
Again, When in Doubt...
Once again, if you suspect spoilage or contamination, please, throw it out.
* Note: this is the FDA's rule. Other agencies may have variations on it. Additionally, government agencies generally make very conservative recommendations - they're trying to make sure that no one who follows the rules gets sick. Breaking the rules means maybe taking on some risk. That's up to you - just remember, eventually someone gets unlucky, and food poisoning is not fun.
Further Reading/Frequently Asked
The question was: "If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?"
Answer: It depends ...
These are just a couple of questions so you get the general idea that it really is impossible to give a generalized answer to the question.
Considering that only a surprisingly small percentage of the worlds population actually has access to refrigerators and people still eat I think it might be obvious that refrigeration is really not the only way to store food for later consumption.
For a more in depth study of the topic I recommend:
As a more general tip I would stick to common sense. e.g. any food containing raw eggs (Mayonnaise) or food that must by its nature be considered contaminated (store bought raw chicken / raw meat) needs to be handled in a reasonable matter (you should be able to find the correct advise about handling these kinds of foods in any good cookbook) to avoid colonisation to an unhealthy (when eaten - even after cooking) point. On the other end of the spectrum leafy vegetables or fruit bought fresh from a farmers market actually comes with its own protection in the form of beneficial bacteria on the skin and is therefore less likely to be easily (meaning in a short time) colonized by pathogenetic organisms. Learn about your food and learn how to cook and you probably will be safe.
It all depends on measures you have taken to prevent spoiling. There a fair few types of charcuterie that is aged for anywhere from a week to several months. So in a general sense yes CERTAIN foods can be safe to eat even when not refrigerated. The thing is these foods have been prepared in a manner that prevents harmful bacteria from growing.
Salami for instance uses salt to cure the sausage and then also adds further acidity to the environment by the addition of wine. This ensure that harmful bacteria is unlikely to grow.
Biltong and to a lesser extent Jerky as well is pieces of meat that is cured in salt and then to remove the salt a vinegar bath is used to also add further acidity and reduce water content of the meat.
These examples seem to be the exception though as it seems you want to know if food that is not specifically prepared for long term curing is safe to leave outside and to that I would say a resounding NO.
(in reply to a closed question:
The rule of thumb (and of the USDA) is: after two hours in the "danger zone" - temperatures between 5-60c/40-140f - the food has two go. That's the official answer and the only responsible one.
But it's indeed a one-size-fits-all-play-it-safe rule. Bacteria's growth rate rises with temperature, until they start dying around 60c/140f. Two hours in a humid 40c/105f will turn fresh meat into a small civilization. But under 10c/50f there'll hardly be a change.
So as Kate Gregory wrote, the question is where you are, and how cold is it over there. If your food was left covered in cold "storage" temperatures, and in the morning felt cold and firm to the touch and smelled fine, it have stayed unspoiled. Problem is: you can't know. I still might be unsafe. Not all food spoilage shows or smells.
Still, if you consider taking the risk, you should still throw away the ground beef. Bacteria grows on the surface of foods. According to common sense you can make a wholesome piece of meat safe by cooking it and "sterilizing" its surface (only that here you need to be guided not by common sense but by a health expert). But either way - in ground meat the outside and the inside are mixed, and any contamination on the meat was spread all across it before the fearful night. So give up the ground meat and
protected by Community♦ Mar 17 at 21:32
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