5 cups (about 1 1/2 pounds) stemmed seedless green grapes
1/2 teaspoon grated lime zest (1 small lime)
3 1/2 cups lemon-lime soda
8 frozen red grape skewers, for garnish (see Cook's Note)
To make the skewers, simply place 3 to 4 red grapes on each toothpick or skewer, and freeze on a rimmed baking sheet.