1 double pie crust
6 cups peeled, cored and sliced apples
1/3 cup frozen apple juice concentrate, thawed, or 3/4 cup apple juice
2-3 tablespoons flour
1 teaspoon ground cinnamon
1-1/2 cups fresh raspberries, blueberries or strawberries
2 tablespoons cold unsalted butter, cut into pieces
1 egg white whisked with 1 tablespoon water
Combine apples, apple juice concentrate, 2 tablespoons flour (3 if using apple juice), and cinnamon in a large bowl. Set aside for 10 minutes. Preheat oven to 350 degrees.
Place pastry in pie pan, pour berries in making one thick layer. Turn apples into the shell and smooth the top. Dot the filling with the butter. Lightly moisten the rim of the pie shell. Invert the top pastry over the filling, center. Press the top and bottom pastries together along the dampened edge. Trim the pastry with knife, leaving an even 1/2 inch overhang, sculpt the overhang into an upstanding ridge. Poke several steam vents in the top of the pie with a fork or knife. Brush the top of the pie with egg white mixture.
Place the pie in the center oven rack and bake for 45 minutes, then rotate the pie 180 degrees, so that the part that faced the back now faces the front. Slide a baking sheet onto the rack below to catch any drips. Continue to bake until the top is golden brown, the apples are tender and the juices bubble, about 30 minutes.
Transfer pie to wire rack and let cool for at least 2 hours before serving.
