Prep and chill the butter. If using a food processor, cube 1 cup butter and chill it in the fridge until ready to use.  If using a large bowl, use a cheese grater to grate the butter and place it in a small bowl in the refrigerator until ready for use.

Pulse with a food processor or use a pastry blender to cut in the cold butter until pea-sized pieces are incorporated into the flour mixture.  Do not overmix, or the butter will begin to melt and the pie dough will be greasy.

Add 1 cup sourdough starter and pulse or stir until the pie dough comes together.  

Turn the pie dough out onto a lightly floured surface and use a bench scraper to fold it over onto itself until all the flour is incorporated.  Do not knead. Kneading will cause the butter to melt and the dough to become greasy and sticky.

Cut the dough into two equal pieces and shape it into discs. These two discs of pie dough will make the top crust and the bottom crust. Wrap each disc with a piece of plastic wrap and chill in the fridge for at least an hour or up to 3 days before use.  

Grease and flour a 9" pie plate.

Prepare a lightly floured work surface and use a floured rolling pin to roll out the pie dough. The pie dough should be 1/8" thick and 2-3 inches wider than the pie plate.  So, for a 9" pie plate, the dough will be rolled into a 12" circle.

Drape the dough over the pie plate and gently fit it without stretching, so the sides drape over the edge

Use scissors to trim around the edges if so everything is even.

Crimp the edges or press with a fork.  * If it takes longer than 5 minutes to roll and set the dough in the pie plate, chill the pie plate and dough for 30 minutes before filling it and baking.  This will help the pie crust maintain its shape.

Add the pie filling. Make sure it is completely cooled.  Follow the baking instructions for the time and temperature of the particular pie you are baking.

Line the chilled dough in the pie plate with parchment paper and fill it with dry beans or pie weights so the pie crust doesn't shrink when you blind-bake it.  Do not skip this step or the crust will shrink and be ruined.

Blind bake the pie with the weights in place for 15 minutes.  Then lift the parchment paper and weights out of the pie dish, poke holes in the bottom of the pie crust with a fork, and return to the oven at 375F to bake 15 minutes longer or until the pie crust is golden brown for a fully blind-baked crust.  For a partially blind baked crust,  only bake for 7 minutes after the parchment paper and weights have been removed.

The next step depends on the kind of pie you are making.  For pies that will be baked further, like quiche or pumpkin pie, add the pie filling immediately and return to the oven to finish baking the pie.  For no-bake pies, allow the sourdough crust to cool completely before adding the pie filling.