Pie problems are a common call at AnswerLine. I had a little time recently, so I thought I’d do a little research to help me answer callers questions. I used our Keys to Good Cooking book by Harold McGee and did a bit of reading.
Probably our most common call is about soggy bottom crusts on a pie. The book had several solutions for this issue. I was surprised when I read the first tip for a crisp bottom pie crust. McGee suggests using a crust recipe that includes egg. He states that a flaky crust (baked without egg) more easily adsorbs liquid. That makes sense, if you think about it. His second tip was one we often suggest. Blind bake the crust–which is baking a pie crust without the filling inside. You can line the crust with parchment paper and use either dry beans or pie weights to prevent the crust from shrinking or puffing up while baking. McGee also suggests coating the pre-baked crust with an egg wash and returning the crust to the oven to dry the crust before filling and baking the crust fully.
Of course, you can come at this problem in a different direction. Instead of treating the pie crust, you can ensure that the filling is precooked and thickened before adding it to the pie crust. Fruit fillings often release a lot of liquid during the baking time and if you have not added enough thickener, you can have a really runny pie. If you thicken the filling before placing it in the crust, you can reduce the chance of a soggy bottom crust.
Another issue that bakers have is taking a custard pie out of the oven and having the custard become thin and watery. This happens if you don’t heat the custard filling hot enough to destroy an enzyme found in the egg yolk that can liquefy the custard. Bake the custard pie to 180°-190° F to destroy the enzyme.
Use these tips if you want to cure a soggy bottom.