Blackberry Pie Ii - cooking recipe

Ingredients

4 1/2 cups fresh blackberries, rinsed and drained
1 1/2 cups white sugar
1/4 cup tapioca flour
1 recipe pastry for a 9 inch double crust pie
1 egg white, beaten
1 tablespoon white sugar

Preparation

Mix tapioca flour and sugar together, and blend mixture into the berries.
Line a pie dish with pastry. Pour filling into pie shell, and cover with top crust. Seal edges by pinching or fluting the edge. Brush top with egg white and sprinkle with a little sugar. Cut slits in top to allow steam to escape.
Bake at 350 degrees F (175 degrees C) for 30 to 40 minutes, until pie is golden brown and bubbly.