It's not always necessary to blind-bake apple pie, but some bakers do. Blind-baking is when you bake the pie crust before adding the filling. The term usually refers to pie crusts made from dough. Graham cracker crusts are often pre-baked to bind the sugar and graham cracker crumbs together, which is essentially the same concept as blind-baking. Pre-baking prevents the crust from falling apart or becoming soggy when the filling is added. .