Sweet potato pie is usually made in what kind of pie shell?

Sweet potato pie is usually made in an open pie shell, without a top crust.

The pastry shell holds a soft, baked custard made from mashed sweet potatoes, eggs, milk or evaporated milk, sugar, and spices. Because the filling sets during baking, it does not need a second crust to enclose it. The exposed surface usually becomes smooth and lightly browned.

This makes sweet potato pie a single-crust or open-faced pie, similar in structure to pumpkin pie and other custard pies. A double crust would hide the filling and is more typical of fruit pies, whose juices and chunks benefit from a top crust or lattice.

Recipes can still vary. Some bakers decorate the surface with pastry shapes, meringue, whipped cream, or nuts, but those additions do not change the basic format. The standard Southern-style pie remains an open shell filled with a spiced sweet-potato custard.