Why is unrefrigerated pumpkin pie unsafe?

Unrefrigerated pumpkin pie is unsafe because it provides an ideal environment for the growth of bacteria.

Pumpkin pies contain ingredients that support bacterial growth, such as milk and eggs. When left at room temperature, the pie provides a warm and moist environment that allows bacteria to multiply rapidly.

Some bacteria that can grow on unrefrigerated pumpkin pie include:

- Staphylococcus aureus: This bacterium can cause a variety of illnesses, including food poisoning, skin infections, and respiratory infections.

- Salmonella: This bacterium can cause food poisoning, which can lead to diarrhea, vomiting, and fever.

- Escherichia coli (E. coli): This bacterium can cause a variety of illnesses, including food poisoning, urinary tract infections, and pneumonia.

- Listeria monocytogenes: This bacterium can cause listeriosis, a serious infection that can be fatal for pregnant women, the elderly, and people with weakened immune systems.

To prevent the growth of bacteria and reduce your risk of food poisoning, pumpkin pie should be refrigerated at 40°F (4°C) or below within two hours of baking. It is also important to keep pumpkin pie covered to prevent contamination from other foods.