Page 102 - United States of Pie

This is the method that I swear by. I rely on two starches: flour
and cornstarch. Other bakers also use tapioca. Each has its
strengths. There are times when I will use a combination of two

starches.

FLOUR: Every pie baker has this on hand, which is a definite
plus. The drawback to flour is that it will cloud an otherwise

translucent filling, making it unwise to thicken a berry pie
entirely with flour. Because of this, I frequently use a mixture of
flour and cornstarch. Flour is the ideal thickener for apple pies,
however, which contain rather opaque pieces of fruit.

CORNSTARCH: This thickener is flavorless, clear, and smooth,
making it ideal for some berry pies. But be careful: cornstarch
will not thicken highly acidic fruits, such as sour cherries or
cranberries. Cornstarch also has twice the thickening power of
flour, meaning you will need to use only half as much.

TAPIOCA: Tapioca, in flour or quick-cooking form, gives pies
that shiny, almost commercial finish. But its thickening power
diminishes over time, so the pie should be eaten relatively
quickly. It is also important to let the fruit mingle with the tapioca
for around 15 minutes before baking to soften the tapioca. Quick-

cooking tapioca will leave little pearls of tapioca suspended in
the thickened juice. I have always found this disconcerting, so
that is why I have avoided it. You can, however, buy tapioca flour
at an Asian grocery, or simply process quick-cooking tapioca in a
coffee grinder or food processor, to solve this problem.