How Long Can Pizza Sit Out And Why?

logo by Editorial Staff | Updated on October 1st, 2023

We’ve all faced the dilemma of what to do with leftover pizza. In this comprehensive guide, we’ll delve into the intricacies of pizza storage and safety, leaving no slice unturned. Discover the science behind why pizza left out can be a recipe for disaster and gain valuable insights to ensure your next pizza experience is not only delicious but also safe.

Is it Safe to Leave Out Pizza?

When it comes to perishable food like pizza, safety is paramount. According to the United States Department of Agriculture (USDA), leaving pizza out at room temperature overnight is a risky choice. This applies even if your pizza lacks meat ingredients. The culprit often lies in the cheese, a major component in most pizzas, which can become a breeding ground for foodborne pathogens.

person picking sliced pizza

How Long Can Pizza Be Left Outside?

The timing of pizza consumption is crucial. Leaving pizza out in the open can pose health hazards. Generally, pizza can be left out for approximately 2 hours before it becomes a potential health risk. It’s worth noting that pizza is often enjoyed straight from a hot source, like an electric oven or a wood-burning oven, which can influence its shelf life.

Understanding Why Pizza Sits Out for So Long

Pizza’s widespread popularity can be attributed to its affordability and convenience. However, its high levels of salt, fat, and food energy, with approximately 5,101 mg per 36cm (14 inches), can have health implications. Studies have linked excessive pizza consumption to cardiovascular disease and intestinal cancer. Balancing your pizza indulgence with a healthy diet is essential for your well-being.

Identifying Pizza Toppings That Promote Bacterial Growth

Bacteria thrive on sweet foods, making pizza, especially those with sweet sauce and gluten-heavy dough, a prime target. Toppings like pineapple, tomatoes, and other fruity options can exacerbate the situation. Cheese is also a favorite among mold and bacteria. If you’re a fan of cured meats like pepperoni, they tend to be more resilient in the face of bacterial growth.

Is it Safe to Eat Pizza Left Out Overnight?

In simple terms, eating pizza that has been left out overnight is not safe. Following USDA guidelines is advisable, which means avoiding items left unrefrigerated overnight. Attempting to salvage it by reheating or scraping off the top layer won’t help since bacteria may have already infiltrated the deeper layers of the dough. To enjoy your pizza the next day, store it in the refrigerator, where it can remain safe to consume for two to three days.

The Consequences of Consuming Bad Pizza

Pizza can be a source of food poisoning, leading to symptoms like nausea, diarrhea, vomiting, and illness. Eating pizza that’s been left out of the fridge for too long can result in severe food poisoning symptoms. The severity of these symptoms depends on the quality of the pizza and how your digestive system deals with the bacteria. While foodborne illness from pizza is not usually life-threatening, it can be quite unpleasant.

Can Reheating Pizza Kill Bacteria?

There’s a belief that reheating pizza can eliminate bacteria. While reheating at temperatures above 165 degrees F can destroy most bacteria, it doesn’t necessarily make the pizza completely safe to eat. Even if bacteria are killed, the toxins they produce remain in the food, potentially causing food poisoning symptoms. Moreover, reheating multiple times can increase the concentration of toxins and bacteria.

How to Identify Spoiled Pizza

Your senses are your best tools for identifying spoiled pizza. A hardened, dry texture, while not necessarily dangerous, can indicate that the pizza is no longer at its best. Spoiled pizza may also emit an unpleasant odor and develop mold if left for an extended period. Bacterial growth may not be visible until it’s well underway. If in doubt, it’s safer to err on the side of caution.

Food Poisoning and Bacteria

Consuming pizza with bacteria can lead to illness, depending on the type of bacteria and how long the pizza was left out. Bacteria like Bacillus cereus can cause stomach discomfort and digestive issues within hours. Listeria, though slower to develop, is tenacious and can continue growing in various conditions. Salmonella can be contracted if pizza is undercooked or contaminated equipment is used. Staphylococcus aureus can produce toxins that are heat-resistant.

Storing Leftover Pizza

To keep leftover pizza fresh in the fridge, use a sealed container or bag. While the original box is fine, it may dry out the pizza. A sealed container preserves moisture, resulting in better-tasting reheated pizza. Leftover pizza can stay in the refrigerator for three to four days before quality deteriorates. Alternatively, freezing it in a tightly sealed container or bag can extend its shelf life to approximately two months.


Pizza is a beloved fast-food staple, but its safety and shelf life require careful consideration. Spoiled food poses health risks, so it’s essential to be informed. While indulging in pizza is enjoyable, moderation and proper storage are key to a safe and satisfying experience. Being aware of the potential risks associated with leftover pizza can help you make informed choices and enjoy this favorite treat responsibly.


Editorial Staff

Our writers, editors, content managers, and SEO specialist. We all take part in crafting amazing articles. We spend hours ensuring that each article is based on facts, researched, and thorough. You'll never want to click the back button to look for more answers other than here!