A double crust pie is simply a pie with two crusts. You’ll find many single crust pies, like pecan and pumpkin, as well as many savory pies like quiches made with a bottom crust. Occasionally, a deep-dish pie features a top crust, and not a bottom one. This is the case with some meat pies, too.
Conversely, the double crust pie has two crusts, a top and bottom one, that together form a seal around the ingredients. This can help keep juices from coming out of the pie, though a little bit might escape from venting in the top crust. Again, you'll find both sweet and savory versions of the double crust pie. Some pizza restaurants even specialize in pizzas with a top and bottom crust, as a variant on deep-dish pizza.
If you’re making a double crust pie, an important step is making certain that the top and bottom crust are sealed together. Pressing the bottom and top crusts together with fingers, with a fork, or with other instruments that make a decorative crust, can accomplish this. Sealing the two crusts together is important since otherwise, any liquid in the pie ingredients may leak underneath the bottom crust, or merely onto a baking sheet upon which the pie sits. If you overfill, or use particularly juicy ingredients, you’re more likely to get leaks.
In many cases, the double crust pie uses the same type of pastry for both top and bottom layers. There are a few exceptions. For instance an apple pie topped with a loose brown sugar, flour and butter topping, is still a double crust pie. Unlike the standard double crust, the two crusts are made of different ingredients.
Another form of double crust pie that is quite attractive is a lattice crust. Instead of rolling out a round circle of dough to top the pie, the dough is rolled out and cut into strips. These are then layered, usually in a crisscross pattern, across the pie. Lattice crusts can be particularly lovely when the pie’s ingredients are attractive. For instance, most berry pies are fantastic for lattice crusts.
This type of crust tends not to work with fruit that will harden if it is exposed directly to oven heat. An apple pie with a lattice crust may not to be a good idea, since the exposed apples on top will get hard and crispy, instead of cooking to softness. This also depends upon the amount of separation in your lattices.
When you’re using a recipe for your piecrust, be sure to check it to see exactly how much piecrust you will make. Generally, a single crust for an 8-inch (20.32 cm) pie dish is composed of a third a cup of shortening, and a cup of flour. A single crust for a 9 or 10-inch (22.86- 25.4 cm) pie dish, especially a deeper one usually calls for a half a cup of shortening to one and a half cups of flour. Both usually add a little cold water. Gauge measurements and appropriate ingredient amounts by these standards so you make enough, but not too much crust for your pie.