Serving a pumpkin pie with a soggy crust won't thrill your dining companions. Keeping the crust crisp on a pumpkin pie is more of a challenge than with most other pies because the custard filling is primarily liquid and the crust easily absorbs liquid. Another factor in keeping pumpkin pie crusts from becoming soggy is to not overcook the filling, which causes water to be expelled from proteins in the eggs and milk.
One way to keep the crust on your pumpkin pie from getting soggy is to use the blind baking method and precook it. Weight down the crust with pie weights or dried beans on parchment paper before baking to keep the crust from puffing up in the center, and bake it for 15 minutes at 425 degrees Fahrenheit until it's fully cooked. Alternatively, prick the bottom of the pie with a fork before pre-baking it. Cool the crust completely before adding the filling and baking it in the oven at approximately 350 degrees. If the edges of the crust begin to get too brown, cover the exposed crust with strips of aluminum foil or a pie crust shield.
Pie on a Hot Sheet
Many recipes suggest baking pie in a hot oven for 15 minutes so the crust sets and quickly cools. The problem with using this method for pumpkin pie is the custard filling also cooks quickly, releasing liquid into the crust and shrinking away from the edges. The result is a soggy crust and a space between the crust and the filling. To rectify this problem, place the pie on a hot stone or sheet inside the oven and cook it at 425 for 15 minutes instead of 450 degrees. The burst of heat is more directed toward the crust, allowing it to set without overcooking the filling.
Seal the Deal
Another way to keep the crust of a pumpkin pie crisp is to create a barrier between the crust and the filling. To do this, brush the crust with a beaten egg or egg white mixture. For best results, put the coated crust in the freezer 10 minutes before filling and baking the pie. As the pie cooks, solitary proteins in the egg white bond to each other and form a network of connected proteins that act as a barrier and keep moisture from reaching the crust.
Cook the Filling
Cooking or partially cooking the filling before putting it in the pie crust allows much of the moisture to evaporate out of the filling. Thicken the filling in a pot over medium-low heat on the stove before adding it to the crust to be baked. If you choose to cook both the crust and the filling separately, cooking the assembled pie 10 to 15 minutes in the oven sets the filling in the pie shape, giving it the look and feel of being entirely cooked in the oven. Even if you don't cook the filling, heat the filling before adding it to the crust to shorten the overall cooking time.