A simple and satisfying after-school snack.
In a large bowl, sprinkle 1 envelope unflavored gelatin over cold water; let stand until softened, about 5 minutes.
In a small saucepan, bring 1/4 cup water to a boil over medium-high. Pour over gelatin mixture; stir in grap juice.
Divide blueberries evenly among four 6-ounce serving glasses; pour in gelatin mixture, pressing blueberries to submerge them completely.
Refrigerate until set, at least 1 hour (and up to 5 days, covered).
