The three most common starches used to thicken the fruit juices of a pie are flour, tapioca, and cornstarch. I prefer cornstarch because I find that it actually enhances the flavor of the fruit.But as any starch in excess dulls the fresh fruit flavor and can make the texture gummy, I like to let the cut fruit sit with sugar for at least 30 minutes, drain the syrup that forms, reduce it by 1/2 to 2/3 or until very thick (I like to use the microwave but be sure to use a large liquid measure sprayed with non-stick vegetable spray to keep it from boiling over) and add it back to the fruit filling.This way only about 1/3 the usual amount of thickener is required, the pie is just as juicy, and the bottom crust crisper.
