Line pie pan with bottom pastry. Fill with berries. Mix sugar, salt, and flour; sprinkle over berries. Spoon drops of lemon juice over all. Put on top crust. Bake in very hot (450 degree) oven for 10 minutes. Reduce heat to 350 degrees and bake about 30 minutes more.
Optional: Last 15 minutes of baking, brush pie top with whisked egg white and sprinkle a bit of sugar atop.