Pumpkin Pie

Pumpkin pie must be refrigerated, and it keeps 3–4 days. This is the most commonly ignored storage rule of the American holiday season.

Cool the pie after baking for no more than two hours, then refrigerate it loosely covered. Leaving a pumpkin pie on the counter overnight — which a great many households do every November — is not safe, however traditional it is.

Cover it loosely rather than sealing it airtight while warm, which traps steam and makes the crust soggy. Once fully chilled, cover it properly.

Pumpkin pie freezes well for 1–2 months. Freeze it unwrapped until solid, then wrap tightly, and thaw overnight in the refrigerator.

Serve it cold or at room temperature, but return leftovers to the fridge within two hours of the pie coming out.

The reason pumpkin pie needs refrigeration and apple pie does not comes down to one word: custard.

Pumpkin pie filling is eggs and evaporated milk or cream, baked until set. That is a custard, and custards are high-protein, high-moisture, low-acid foods — the profile that supports bacterial growth most readily. The USDA's guidance is explicit that egg-and-milk-based pies must be refrigerated, and it applies to commercially baked pies as well as homemade ones.

A fruit pie, by contrast, is acidic and high in sugar, both of which inhibit bacterial growth, and it contains no significant protein. That is why apple and cherry pies can sit on a counter for a day or two and pumpkin pie cannot.

There is one exception worth knowing. Some commercially produced pumpkin pies are formulated with preservatives and processed to be shelf-stable, and are sold unrefrigerated. If you bought a pie from an unrefrigerated display it can stay out until cut — but once cut, refrigerate it. If it was sold refrigerated, keep it refrigerated.

Discard on any mold, a sour or fermented smell, a filling that has gone watery and is weeping significantly, or a slimy surface. Small cracks in the surface are normal and are just overbaking.