Prepare Baked Pastry Shell. Cool. For filling, in a medium saucepan, combine the 1 cup sugar and the cornstarch. Stir in grape juice and water. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat. Cook and stir the mixture for 2 minutes more.
Remove from heat. Stir in lemon peel and lemon juice. Reserve 1/3 cup hot mixture for meringue; set aside to cool.
Separate eggs; set whites aside for meringue. Beat egg yolks slightly. Gradually stir 1 cup of the remaining hot mixture into the yolks; return all to saucepan. Bring to a gentle boil. Cook and stir for 2 minutes more. Remove from heat. Pour into baked piecrust.
For meringue, beat egg whites until soft peaks form (tips curl). Beat in the remaining 2 tablespoons sugar and reserved filling. Beat until stiff peaks form (tips stand straight).
Carefully spread meringue over the hot filling in piecrust; seal to edge. Bake in 350 degree F oven for 15 minutes or until meringue is golden. Cool on wire rack. Cover and store in the refrigerator. Makes 8 servings.
Stir together flour and salt. Using a pastry blender, cut in shortening until pieces are pea-size. Sprinkle 1 tablespoon of the water over part of the mixture; gently toss with a fork. Push moistened dough to the side of the bowl. Repeat moistening dough, using 1 tablespoon of the water at a time, until all the dough is moistened. Form dough into a ball. On a lightly floured surface, use your hands to slightly flatten dough. Roll dough from center to edge into a circle about 12 inches in diameter. To transfer pastry, wrap it around the rolling pin. Unroll pastry into a 9-inch pie plate. Ease pastry into pie plate, being careful not to stretch pastry. Trim pastry to 1/2 inch beyond edge of pie plate. Fold under extra pastry. Crimp edge as desired. Generously prick bottom and side of pastry in pie plate with a fork. Prick all around where bottom and side meet. Line pastry with a double thickness of foil. Bake in a 450 degree F oven for 8 minutes. Remove foil. Bake 5 to 6 minutes more or until golden. Cool on a wire rack.