Even though pie crust is made from just a handful of ingredients: flour, salt, fat and liquid; it is a very complicated procedure.
Basically, the fat is marbled through the flour and ideally forms a flaky, crisp pastry when baked.
Pie dough shouldn't be confused with tart dough, which is sweeter.
Pie dough is made by cutting the fat into the flour, mixing in just enough water to hold the dough together. Too much mixing toughens the pastry by lengthening the gluten in the flour. So, mixing the liquid into the dough should be minimal, just enough to hold the pastry together and then chill, chill, chill.
Temperature is KEY. Keep everything cold, the flour, the fat, the liquid and the pie pan.
Start refrigerating ingredients before they are mixed together. Chill flour, fat and water. Even chill the pie pan!
Start with a pie pan, either stainless steel, glass, porcelain. Recipes suggest not greasing the pan, although I like to grease it to prevent sticking pieces of dough. When cooking the pie, cook in the bottom third of the oven to make a crisper crust and to not over-brown the top crust.
LIQUID - Some recipes call for vinegar/lemon juice or even vodka in place of half of the usual water. Vinegar offers some benefits. The acid in the vinegar slows the gluten from lengthening. The Vodka does similar things. (There are no residual flavors once the dough is baked.) Some people swear by vinegar in pastry, others are happy with just water. If you chose to use it, add 1 tsp per cup of flour.
FAT - Here is where there is some argument from the purists. Butter vs Shortening or Lard.
Butter contains 80% (approximately) fat 20 % water. Shortening and Lard contain 100% fat.
(Currently, there are hydrogenated free shortenings, trans fat free Crisco etc to resolve health concerns.)
When the shortening melts and cooks in the dough, it provides a tender crumb. When the butter melts, the water in it, evaporates and causes the dough to be flaky.
Those who choose to use butter instead of shortening, choose unsalted butter is the preferred choice among bakers, only second to European butter.
Shortening is the ultimate choice, but some bakers feel that a mix of 2 parts butter to 1 part shortening produces the best crust possible.
3 cups all purpose flour
2 T sugar
1 3/4 tsp salt
1 cup chilled unsalted butter, cut into 1/4 inch cubes
2 T shortening (if not using shortening, replace with additional butter)
8 T ice water (may need more or less water)
3 tsp apple cider vinegar
Mix flour, sugar and salt and chill mixture.
Chill shortening and butter, after cutting into tiny pieces.
Mix 3 tsp vinegar and 5 T ice water in glass. Chill.
Chill pie plate.
Cut fat into flour and salt mixture.
Drizzle in the vinegar/water mixture and press dough together. You might need more water, but add just enough to make the mixture hold together.
Place in a large (gallon) plastic bag or covered bowl and press into a disk shape and chill for 30 minutes.
Leaving the disk in the bag, slice open the bag, keeping both sides of the bag intact.
Or use 2 pieces of wax paper.
Roll the dough flat.
Try not to add additional flour when rolling the dough. Chill pastry again for 30 minutes.
Remove from fridge and place dough in the pie pan.
To make a single layer crust pie:
Prick the bottom of the pan with fork, flute the edge of pan as desired and place a sheet of parchment paper on top of dough. Fill with beans and freeze for 30 minutes.
Preheat oven to 350. Once oven is hot, add the pie pan with dough and bake.
Remove from oven and cool. Add ingredients.
To make a double layer pie:
Make 2X the amount of dough. When chilling the dough disk for the first time, make 2 disks instead of one.
Follow the remaining ingredients.
Line pie pan with dough. Fill with filling. Top with top crust.
Cut slits for steam to escape, seal edge and place in freezer for 30 minutes.
Remove from freezer and brush with cream, milk or beaten egg.
Bake in hot oven for 45 - 55 minutes, until brown.