In a large bowl, whisk together the flour and salt. Add the shortening and butter; use a pastry blender to cut the butter and shortening into the flour until the mixture resembles a coarse meal with a few pea-sized pieces of butter/shortening throughout.
Sprinkle the vinegar and water over the mixture. Mix with a fork, just until the mixture holds together when squeezed in your palm - it will still look crumbly in the bowl. Depending on the weather, you may need to add a bit more water, 1/2 tablespoon at a time, until you reach the correct consistency.
Turn the dough out onto a floured board. Pat into a circle; cut in half. You can now use the dough right away or wrap in plastic wrap and chill in the refrigerator for 30 minutes or until ready to use, up to a day.
Place one half in the refrigerator while you roll out the second half on a floured surface to fit your pie plate. Remove second half from fridge and roll out to top the pie, baking according to your recipe.
If blind baking, bake at 450°F for 8-10 minutes or just until golden.
Notes
For one single-crust pie, either halve the recipe or use half and freeze the other half for later.Before I start making the crust, I like to fill a glass with ice water and place it in the refrigerator. This way my water is very, very cold when I need to add it to the recipe.If you are making your pie crust on a hot day, I recommend chilling the dough for at least 30 minutes before rolling it out in order to make it easier to work with and to keep the butter from getting too warm.Makes 1 double-crust or 2 single-crust 9- or 10-inch pies.