In a large bowl, combine the flour, cream of tartar, and salt. Keep the flour cold by chilling it briefly if needed.
Cut in the Crisco by hand until the mixture resembles coarse crumbs.
In a small bowl, mix the cold water, beaten egg, and vinegar.
Gradually add the liquid to the flour mixture, one tablespoon at a time, until the dough just comes together. Be careful not to overwork it.
Divide the dough into two discs, wrap in plastic, and chill in the refrigerator for at least 30 minutes before rolling.
Roll out on a lightly floured surface and use as desired for pies.
Tips & Tricks from Grandma:
