It’s the end of the day, and you’re tired. You worked hard all day, so all you want to do is go home, eat dinner, and relax.
But before you can do that, you need to heat last night’s leftovers. Is it safe to reheat food that was left out overnight? Well, the answer may surprise you!
The USDA advises against reheating food that was left out overnight. Various bacteria lurking in the environment threaten your food safety, thriving in between 40-140 °F temperatures. They can double in 20 minutes, so unrefrigerated food goes bad in two hours.
We’ll discuss the dangers of eating food you left out overnight. We’ll also cover some tips on avoiding food poisoning. Stay safe and enjoy your meal!
Is Leaving Food Out Overnight Bad?
Hey, it’s always tempting to eat those leftovers from yesternight, especially if it was a hearty meal. We can’t always finish what we cook, and no one ever wants to waste food. It’s not only bad for the economy, but it’s also immoral. Or is it?
Yes, it’s bad to leave food out overnight because it goes against basic food safety. Bacteria will thrive and grow in the food, making you sick.
You might experience vomiting, diarrhea, fever, or other unpleasant symptoms. Not to mention that it’s just plain unsanitary to have food lying around for hours on end.
According to the FDA, you should not leave food out for more than two hours. That’s the time it takes for bacteria to grow and multiply. You don’t want that on your plate, do you?
Bacterial growth is a significant risk when reheating food you left out overnight. Here are some of the most common culprits:
- Staphylococcus
A group of bacteria found on human skin, Staphylococcus reproduces rapidly and can cause multiple symptoms. The most severe cases can lead to sepsis, a potentially life-threatening condition.
- Clostridium perfringens
This bacterium is usually found in soil and produces toxins that can cause food poisoning. Symptoms include diarrhea, abdominal cramps, and vomiting.
- Listeria monocytogenes
These bacteria cause listeriosis, a severe infection that can be fatal. Symptoms include fever, muscle aches, and diarrhea.
- Salmonella
This bacterium is responsible for salmonellosis, a foodborne illness that often results in diarrhea, vomiting, and fever.
- E. coli
This bacterium is found in the intestines of animals and can cause food poisoning, urinary tract infections, and even death.
How to Store Food Safely
If necessary, put the leftovers in a refrigerator below 40 °F within two hours of cooking them. If possible, reheat them to an internal temperature of 165 °F before serving. You can check your food’s temperature by using a meat thermometer or instant-read thermometer.
You can also keep the food heated to keep it safe, but doing it overnight would be a waste of energy. The more eco-and-cost-friendly approach would be to refrigerate the food.
So, if you can’t finish your meal in one sitting, be sure to put it away in the fridge within two hours of cooking. If you leave it out for too long, you risk getting food poisoning from bacteria that are multiplying on the surface of your food.
What Foods Can Be Left Out Overnight?
The answer, unfortunately, is not all that straightforward. Foods that you can safely leave out at room temperature for a few hours may not be safe if they are left out overnight. A bacterium grows rapidly at warm temperatures, and food poisoning can occur if you eat contaminated food.
So, which foods can you leave out overnight and which should be refrigerated?
The U.S. Department of Agriculture (USDA) has developed a FoodKeeper App that can help answer this question. The app lists specific recommendations for the safe storage of different types of food. According to the USDA, the following foods can be left out overnight:
- Bread, rolls, and buns
- Chips, pretzels, and popcorn
- Fresh fruits and vegetables
- Uncooked tomatoes, potatoes, and onions
- Honey
- Jellybeans
- Microwave popcorn
The following foods are safe when refrigerated:
- Cooked meat and poultry
- Cooked fish
- Eggs and egg dishes
- Milk and milk products
- Sour cream, cream cheese, and yogurt
- Mayonnaise
- Salad dressings
- Baked goods, such as cakes, cookies, and fruit pies
- Spreads, such as peanut butter and jelly
- Casseroles and soups
The following foods should be frozen:
- Fresh meat, poultry, or fish (depending on the type of fish)
- Leftovers that contain cooked meat or eggs, including casseroles, soups, quick bread (such as banana bread), and muffins
- Baked goods that contain any meat or egg, such as custards or quiche
- Cheese spreads, dips, and sauces, including cheese-filled tortellini
- Milk products that are not cooked in a recipe. It’s okay to freeze milk products that are cooked in a recipe, such as a quiche
- Raw eggs and egg dishes. Cook the eggs or egg dishes before freezing them
What if You Left Food Out Overnight in a Container?
According to the Food Safety and Inspection Service of the United States Department of Agriculture, you should never leave perishable food unrefrigerated for more than two hours, even if it’s sealed.
When you leave food out overnight, chances are your food is not safe to eat. Bacteria might have already grown on the food, despite the sealed container. There’s no way the seal protects food from bacterial swarming.
You can’t always see, smell or taste the harmful bacteria that might be in your food. For example, when you leave a container of cooked rice overnight, chances are you won’t detect any odor, and the rice will look fresh. Bacteria most probably grew on the rice, but you just can’t tell by looking or smelling it.
You’ll only know if food poisoning occurs after eating that particular food. If this happened in a restaurant, an entire kitchen will likely get shut down until the issue is resolved. But what if it happens to you or at home?
If you accidentally left a dish out overnight or over an extended period, it’s best to throw it away rather than risk eating it. You don’t want to get sick just because you wanted to eat leftovers.
Will Reheating Food Kill Bacteria?
Reheating food is a pretty effective way of killing bacteria, but there are a few concerns.
First, it’s essential to understand that bacteria don’t just die off at certain temperatures or times. All bacteria are different and have varying survival rates under different conditions. You can kill some harmful bacteria by reheating food to 149 degrees Fahrenheit or higher for a minimum of two minutes.
However, some bacteria can survive reheating. The most common type of bacteria to cause food poisoning is called Bacillus cereus, and it can survive up to three hours at 140 degrees Fahrenheit.
So, while reheating food will kill most bacteria, it’s not guaranteed to work. The best way to ensure your food is safe is to properly store and refrigerate leftovers as soon as they are cooled off from the initial cooking process.
Moreover, reheating food can sometimes make the bacteria even more potent. So, if you do get sick after eating reheated food, it’s best to see a doctor.
Also, leaving out food overnight allows bacteria enough time to do the damage. Some will have produced poisons and aflatoxins that linger on even after reheating food to kill off the causative bacteria.
Final Thoughts
If you want to know if it’s safe to eat food that was left out overnight, the answer is no. Since bacteria grows rapidly at temperatures between 40 and 140 degrees Fahrenheit (known as the danger zone), foods should not be in this temperature range for more than two hours.
Take my advice, always refrigerate leftovers as soon as possible, and then reheat them to a hot temperature before serving. Finally, throw away any leftovers that were kept out for more than two hours.