Blueberry Pie Filling

From Joy of Cooking, 1953 ed., p. 569

4 cups fresh (or frozen) berries

Combine:

about 1 cup granulated sugar
4 T. flour
2 tsp. quick-cooking tapioca
1 1/2 T. lemon juice

Sprinkle above ingredients over berries and stir. Pour into pie crust and dot with butter. Allow to stand for 15 minutes before adding top lattice crust and baking 450 deg. for 10 min., then 360 deg. for about 30 min.