For a crisp bottom crust, be sure to bake pies on the lowest rack of a thoroughly preheated oven.
Use heavy gauge steel or aluminum pans for the best results. Glass and ceramic pans also work well, and glass has the added advantage of letting you see how brown the bottom crust is getting. However, pies baked in glass or ceramic pans should be baked at about 25 degrees less oven heat than the recipe calls for.
Foil pans are often not strong enough to hold certain fillings firmly in place. They also overheat because they are so thin. But they are very welcome in emergencies.
Beware of some of the newer finishes in bakeware; predarkened tin-oxide pans brown pies and breads too quickly and you have to compensate by shortening the baking time. White Teflon-finished pans, on the other hand, often produce pastries and breads that are pale and colorless.
UNFILLED PIE SHELLS
Unfilled pie shells should be baked at 425 degrees for 12 minutes for a tart shell, 18 to 20 minutes for the Basic Pastry - or until lightly browned. Let them cool before filling them.
If the dough has been fitted to the pan loosely without stretching, the pie shell is less likely to buckle up during baking. Many books recommend that unfilled pie shell be covered with foil and then weighted down with beans or rice to prevent pastry from puffing up in spots while it is baking. I have found though, that this method often creates an undesirable moist bottom. I prefer to prick the bottom all over with a fork before baking and then, after the pie shell has been in the oven for about 5 minutes, to open the door to see if any spots have begun to swell; if so, push them down gently. Repeat this again, if necessary, after 5 minutes and you will have a dry, flaky pie shell.
FILLED PIES AND FILLED PIE SHELLS
Filled pies are generally baked at 425 degrees for the first 10 minutes and then at 350 degrees for the remainder of the baking time. The higher baking temperature at the beginning helps produce a crisp crust. Baking temperatures vary, of course, with specific pies, so follow the instructions given with the recipe.
If the tops or edges of a piecrust begin to brown too quickly, cover the pie lightly with a piece of foil and continue baking.