I always use either a pie crust shield or aluminum foil to protect the edge of the pie crust and to keep it from over browning or burning. If you do not have a pie crust shield, you can simply cut a circle out of aluminum foil, a little larger than the top of your pie. Fold the circle in half and cut out the center. You'll want to have an aluminum foil ring that is about an inch wide around the edges. Lay it on top of your pie and gentle bend the foil so it protects the exposed pie crust. You can remove the foil for the last 5 to 10 minutes, if you desire a little browning on your pie crust.