Is Pasta That Was Left Out Overnight Safe To Eat The Next Day?

There are a lot of mistakes you can make when cooking pasta, but that isn't the only time when things can go wrong. For instance, say you get caught up watching your favorite show after dinner and then head off to bed, completely forgetting to put away your leftovers. Now, if the pasta doesn't contain meat, you might be tempted to box it up and put it away to eat later. Unfortunately, even if the pasta looks alright, it turns out you can get pretty sick from eating it if it's been left out for too long.

The danger comes from a bacteria called Bacillus cereus, which can exist as spores on dry pasta. While not immediately dangerous, these spores can survive the cooking process and begin to multiply on cooked pasta, releasing harmful toxins as they do. Refrigerating pasta at 40 degrees Fahrenheit or below can cause the bacteria to become inactive, but they will begin multiplying again when the pasta is reheated.

Food poisoning from Bacillus cereus can cause two types of illnesses: diarrheal syndrome and emetic syndrome. Diarrheal syndrome can take effect anywhere from six to 15 hours after consumption and usually entails cramping, abdominal pain, and diarrhea, while emetic symptom comes with vomiting, nausea, and sometimes diarrhea a half hour to five hours after consumption. Although the food poisoning is often not severe, people have died from it, including a 20-year-old who ate five-day-old spaghetti that had been sitting at room temperature and a young child who died after eating four-day-old pasta salad.

Whether you're making easy homemade pasta or using pasta from a box, once it's cooked, the clock is ticking on how long you can safely keep it out. According to Food Safety.gov, bacteria multiply rapidly in the "danger zone" of 40 degrees to 140 degrees Fahrenheit. Because of this, it's essential to keep food hot after cooking and never let it sit at room temperature for more than two hours. Ideally, you should cool it quickly and put it away as soon as you're done with it.

To cool pasta quickly, you can spread it on a sheet tray to allow heat to dissipate more evenly, or you can divide it into smaller portions and put it into the fridge while still hot. To prevent the noodles from sticking together, add a bit of olive oil or butter. Don't worry; hot foods in smaller portions are okay to put directly into the refrigerator. Once the pasta is in the fridge, it should be eaten within three to four days. However, it can also be frozen for up to two months in an airtight container. 

This also goes for pasta salad, which likewise should never be left out, even if you're at a get-together. You can even freeze pasta salad to save it for longer; however, when it's stored in the fridge, it should be consumed within a couple of days.