Baking the quiche for too long

Here's a well-kept secret. Your quiche should be underbaked. While it may appear counterintuitive, paying attention to a few cues will save you from the overbaked custard. It's difficult to give broad cooking time recommendations. The length of time it takes your quiche to fully cook depends on the size of your pan and the temperature of your oven. Most quiche recipes will call for at least 1 hour of baking time (about 60 to 75 minutes).

Underbaking is preferable. Remove from the oven when the custard is mostly set but still has a little jiggle in the center. It will continue to cook through, achieving the proper consistency by the time it cools, a process known as carryover cooking. If you're still unsure about when to remove the quiche from the oven, use a probe thermometer. The reading in the center should be between 175 and 180 degrees.