Pies and tarts start with a layer of crust or pastry lined in the bottom of the pan, but what is the difference between crust and pastry? The terms pie crust and pie pastry are sometimes used interchangeably; however crusts are typically made with crushed cookies and pastry is normally made with flour, fat, and liquid.
Crust: Crusts are an alternative to pastry when making pies and tarts. Crusts are normally made with crushed cookies such as graham crackers, chocolate or vanilla wafers, gingersnaps, and shortbread. The crushed cookies may be combined with nuts along with butter or eggs, and are normally “patted” into the pan. Crusts are quick and easy to make and provide a “rustic” alternative to pastry and are the traditional choice to many cream pies and refrigerator pies.
Pastry: Pastry, also called pie dough, is a combination of flour, a fat such as oil, butter, lard, or shortening, a liquid of water or milk, and sometimes eggs and sugar. The pastry ingredients are mixed together, rolled fairly thin with a rolling pin, and fitted into the pan. The primary goal when baking pie is to create pastry that has a crisp, flaky crust. Tart pastry will generally be sweeter and rolled a bit thicker to support the tart when unmolded.