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.