How to Make It
Combine flour, salt, and sugar in a large mixing bowl. Use a pastry cutter or your hands to incorporate the butter into the flour until only very small pieces of butter remain in the mixture.
Add the apple cider vinegar and half of the water to the dry ingredients. Mix and press with your hands to incorporate. Then add the rest of the water, 1 tablespoon at a time, mixing until the dough comes to together into a smooth and pliable mass.
Knead the dough for 30 seconds, and then cover and refrigerate for 1 hour.
Remove dough to the counter for 10 minutes before rolling out on a sheet of parchment paper and inverting into a pie pan. Trim the edges and use the extra dough to fill in any gaps or cracks in the border around the perimeter of the crust. Press the cracks in the dough with your fingers so the dough comes back together wherever it has broken. Crimp the edges as desired. Prick the bottom of the crust all over with a fork, and return to the refrigerator for another 20 minutes.
To Pre Bake the Crust: Preheat oven to 350°F. Bake crust until slightly golden brown, about 20 minutes.
The gluten-free all purpose flour you use must contain xanthan gum—other gluten-free flours will not work without this ingredient. This pie dough is exceptionally crumbly and prone to crack, but if you are patient and press the cracks in the crust together with your fingers, the surface will eventually be perfectly intact. Also, it’s important to note that gluten-free piecrusts are best on the day they are made, as the crust tends to become tough over time.