1. Boil cranberry juice in heavy large saucepan until reduced to 1 cup, about 50 minutes. Place cranberries in large bowl; pour hot reduced juice over. Stir to coat. Cool. (Can be made 3 days ahead. Cover and refrigerate. Remove from refrigerator 1 hour before serving.) Just before serving, stir grapes, lemon juice, and peel into cranberries.