You generally should not leave most apple pies out overnight if they contain eggs or dairy in the filling (like custard-style fillings, cream, lots of butter, or cheese).

Quick Scoop

  • For classic homemade apple pie with a buttery crust and typical egg/dairy-based pastry , food-safety guidance treats it as a perishable dessert: it should not stay at room temperature longer than about 2 hours because bacteria can multiply quickly in the “danger zone” between 40°F and 140°F.
  • Leaving that kind of apple pie out overnight (8–12 hours) is considered unsafe, even if it looks and smells fine, because some bacteria can produce toxins that are not destroyed by reheating.
  • Some sources note that certain fruit pies with higher sugar and acidity can be relatively safer at room temperature, but modern food safety advice still recommends promptly refrigerating leftover apple pie to reduce the risk of foodborne illness.

When is it (sometimes) okay?

  • Fruit pies with no custard or cream and a high-sugar, more acidic filling may be relatively less risky on the counter, which is why some bakers still keep a fresh apple pie out for a short time.
  • Even then, food-safety–focused sources often cap safe room-temperature time around 2 hours and recommend refrigerating as soon as it has cooled.

What to do if you left it out

  • If your apple pie sat out all night at normal room temperature, the safest move—especially if it contains any dairy or eggs beyond what is baked into a dry crust—is to discard it rather than risk food poisoning.
  • Reheating an apple pie that was left out overnight does not reliably make it safe, because heat may not destroy toxins produced by bacteria that have already grown.

How to store apple pie safely

  • After baking, let the pie cool just until warm, then move it to the fridge; properly stored, most leftover apple pies keep about 3–4 days under refrigeration.
  • If you plan ahead and want that “room temperature” serving experience the next day, you can refrigerate the whole pie, then bring slices out shortly before serving and gently warm them in a low oven.

Bottom line: For best food safety, do not leave apple pie out overnight; cool it, then refrigerate and enjoy within a few days.

Information gathered from public forums or data available on the internet and portrayed here.