How Long Is Pizza Good For Sitting Out? A Food Safety Expert Weighs In
Leftovers happen! But when it comes to pizza sitting at room temperature, the general rule is: never leave pizza out for more than two hours. After that, it enters the “danger zone” where bacteria can multiply rapidly, increasing the risk of foodborne illness.
The Pizza Predicament: Time vs. Temperature
Pizza, with its delightful blend of cheese, sauce, and toppings, is a culinary masterpiece. However, this very composition makes it a breeding ground for bacteria when left at room temperature for extended periods. Understanding the science behind food safety is crucial to enjoying your leftovers without consequences.
The Danger Zone: 40°F – 140°F (4°C – 60°C)
The danger zone is the temperature range between 40°F (4°C) and 140°F (60°C). Within this range, bacteria thrive and multiply rapidly. Pizza left sitting out falls squarely into this danger zone. Common culprits include:
- Staphylococcus aureus
- Bacillus cereus
- Salmonella
These bacteria can cause a range of foodborne illnesses, from mild stomach upset to more severe symptoms.
Factors Influencing Pizza Spoilage
Several factors influence how quickly pizza spoils at room temperature:
- Ambient Temperature: Warmer rooms (above 70°F or 21°C) will accelerate bacterial growth.
- Humidity: High humidity can also encourage bacterial growth.
- Ingredients: Pizza with meat or creamy sauces is more susceptible to bacterial contamination.
- Initial Condition: Pizza that was already held at room temperature before you received it has a shorter safe window.
Best Practices for Pizza Storage
Protecting your pizza requires proper handling and storage:
- Cooling: Allow the pizza to cool slightly before refrigerating. This prevents condensation buildup, which can make the crust soggy.
- Refrigeration: Store pizza in an airtight container or tightly wrapped in plastic wrap or aluminum foil.
- Reheating: Reheat pizza thoroughly to an internal temperature of 165°F (74°C) to kill any bacteria that may have grown during storage.
Is the Five-Second Rule a Myth?
The five-second rule is largely a myth. While the amount of bacteria transferred in a few seconds might be small, it’s still a risk, especially on surfaces that are not clean. It’s best to err on the side of caution and discard food that has been on the floor.
Visual Signs of Spoiled Pizza
While taste and smell are good indicators, they are not always reliable. Bacteria can be present even without obvious signs of spoilage. However, be cautious if you observe:
- Slimy or sticky texture
- Sour or unusual odor
- Visible mold growth
- Discoloration of the toppings
Can You Trust the Smell Test?
While a strong, unpleasant smell is a clear indication that pizza has spoiled, relying solely on smell is not recommended. Some bacteria don’t produce noticeable odors, and even a good-smelling pizza might harbor harmful microorganisms.
Frequently Asked Questions (FAQs)
What happens if I eat pizza that has been sitting out for too long?
If you consume pizza that has been sitting out for too long, you are at risk of food poisoning. Symptoms can range from mild nausea and stomach cramps to more severe vomiting, diarrhea, and fever. The severity depends on the type and amount of bacteria present, as well as your individual immune system. Pay close attention to your body and seek medical advice if symptoms are severe or persistent.
Does reheating pizza kill all the bacteria?
Reheating pizza to an internal temperature of 165°F (74°C) will kill most harmful bacteria, but it may not eliminate all toxins they produce. These toxins can still cause illness even after the bacteria are dead.
Can I freeze pizza that has been sitting out at room temperature for a while?
Freezing pizza will not kill bacteria; it only slows down their growth. If pizza has been sitting out for more than two hours, it’s best to discard it rather than freezing it. Freezing will not make unsafe food safe.
Is it safe to eat cold pizza that has been refrigerated?
Yes, cold pizza that has been properly refrigerated is generally safe to eat within 3-4 days. Make sure it was refrigerated within two hours of being cooked.
How long can pizza leftovers be stored in the refrigerator?
Pizza leftovers should be consumed within 3-4 days when stored properly in the refrigerator. After this time, the risk of bacterial growth increases, even in refrigerated conditions. It’s best to err on the side of caution and discard any pizza that’s been stored for longer than this period.
Are some pizza toppings more prone to spoiling than others?
Yes, pizza toppings with high moisture content, such as tomatoes, mushrooms, and cooked vegetables, can create a more favorable environment for bacterial growth. Meats, especially those not fully cooked before being added to the pizza, also increase the risk. Be especially cautious with pizzas containing these ingredients.
What is the best way to reheat pizza?
The best way to reheat pizza is in an oven or toaster oven at 350°F (175°C) until heated through and the cheese is melted. A skillet on the stovetop can also be effective. Microwaving can make the crust soggy, but it is a quick option if necessary. Ensure the internal temperature reaches 165°F (74°C) regardless of the method you choose.
Does the type of pizza crust affect how long it stays safe?
The type of crust doesn’t significantly impact how long pizza stays safe. The key factor is the handling and storage of the pizza, regardless of the crust type. The two-hour rule applies to all types of pizza crust.
What are the symptoms of food poisoning from pizza?
Symptoms of food poisoning from pizza can vary depending on the type of bacteria involved. Common symptoms include nausea, vomiting, diarrhea, stomach cramps, fever, and chills. If you experience any of these symptoms after eating pizza, consult a doctor.
Is it safer to leave pizza in a cardboard box than on a plate?
Whether the pizza is left in a cardboard box or on a plate doesn’t affect the rate of bacterial growth. The determining factor is the temperature and time at room temperature.
Can I leave pizza out at room temperature if it’s in a sealed container?
A sealed container might slow down the cooling process, but it won’t prevent bacterial growth at room temperature. The two-hour rule still applies.
Is there any way to extend the safe time for leaving pizza out at room temperature?
No. There is no safe method to extend the time pizza can be left at room temperature beyond two hours. Refrigeration or freezing are the only ways to safely store leftover pizza for later consumption.