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Like all foods, soup has specific guidelines for when it becomes no longer safe to eat. Here is what you need to know about leaving soup out overnight and when soup becomes unsafe to eat.
As a general rule, soup left out overnight at room temperature should be thrown away. When any food substance, including soup, enters the danger zone of 40-140 degrees Fahrenheit and stays there for more than two hours, it should be thrown out. This will help prevent food-borne illness and bacteria.
The bottom line is this: don’t eat your soup if it looks, tastes, or smells funny; store your soup properly in the refrigerator; reheat to 165 degrees Fahrenheit or until steaming; and label the date you put your leftover soup in the fridge on your Tupperware. Doing all of this will help you stay healthy and safe from food-borne illnesses.
The Possible Bacteria in Your Cooked Soup
There are five popular bacteria that can lurk in your soups. Some bacteria produce spores and toxins that are worse for you than the bacteria itself, like Staphylococcus aureus, more commonly known as staph.
Salmonella
The CDC estimates that Salmonella causes about 1.35 million cases of illness a year. Salmonella is a bacteria that resides in the intestines of people and animals and is caught by contaminating foods or liquids or by touching infected animals and/or their stool. (Source)
Salmonella is most often recognized by its symptoms of stomach cramps, fever, and diarrhea. There can also be nausea, vomiting, and headaches. Symptoms can start 6 hours to 6 days after exposure and last 4–7 days. Most people do not need antibiotics and get over it in about a week. However, people who are at high risk may need medical attention. It’s a good idea to go see a doctor if you get bloody stool or if your fever is not going away. For as long as diarrhea exists, you should drink lots of fluids.
Sometimes these symptoms continue after getting rid of the bacteria. It isn’t totally uncommon to have diarrhea for up to several months after getting Salmonella.
E. coli
Like Salmonella, E. coli lives in the intestines of humans and animals. However, most strains of E. coli are actually healthy and needed in order to keep a healthy gut. Because the unhealthy E. coli is spread via feces, it is best to avoid uncooked meats, unpasteurized milk, and swallowing lake water. As always, it is a good idea to wash your hands regularly. (Source)
E. coli has similar symptoms to Salmonella but with little to no fever. It also lasts a bit long in both stages of catching E. coli (anywhere from 3–4 days) and suffering through the symptoms (5-7 days). Vomiting is also much more common for E. coli than for Salmonella. Like with salmonella, you should see a doctor if your stool or vomit is bloody, if your fever persists with diarrhea or vomiting, or if you are vomiting so much you can’t keep down liquids.
As far as treatment goes, the best treatment is time and staying hydrated. Antibiotics are not usually prescribed for E. coli because it doesn’t help more than hurt.
Staph
Staph infections are fairly common because they come in so many different varieties. Most staph bacteria are found in your nose and are harmless as long as you remain healthy. Staph produces a toxin that causes food poisoning. These toxins cannot be boiled or cooked out of food, hence why it is quite a menace and a danger. The biggest prevention of staph is washing your hands. (Source
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The most common symptoms of food-borne staph infection are sudden bouts of nausea, vomiting, bad stomach cramps, and occasionally diarrhea. Symptoms appear 30 minutes to 8 hours after infection and last no more than one day.Staph cannot be passed from person to person. The biggest differentiator between staph and any of the others is that staph is very fast.
Botulism
Botulism is probably more on the scary end of bacteria than the above ones. Botulinum toxin is caused by a bacterial toxin that creates muscle paralysis. In the food world, it is most commonly found in improperly canned, preserved, or fermented foods. (Source)
Botulism is determined by muscle paralysis. When it comes to being passed via food, it includes all of the classics: vomiting, diarrhea, nausea, and stomach pain. However, this can quickly turn into more serious things like muscle weakness, difficulty swallowing, blurry vision, slurred speech, difficulty breathing, and more.
The best prevention is canning food correctly. It is treated with antibiotics and other medicines.
If you or a friend or family member are having symptoms of botulism, see a doctor immediately. It can get very bad and become fatal.
Campylobacter
Campylobacter is the number one bacteria that causes diarrhea in the U.S. Chickens, turkeys, and cows often carry Campylobacter without showing any signs. Milk, fruits, and veggies that have had contact with campylobacter are the biggest culprits. (Source)
Just like all the other food-borne illnesses, Campylobacter symptoms are diarrhea, fever, and stomach cramps. The best treatment is time and water. Symptoms start 2-5 days after infection and last for about 1 week. See a doctor if stool becomes bloody.
