Making these fruit-flavored gelatin desserts from scratch is easy and takes only minutes, but allow at least two hours for them to set in the refrigerator.

1. In a small bowl, sprinkle gelatin over ½ cup cold water; let soften.
2. Meanwhile, place grapes, sugar, and 1 cup water in a medium saucepan. Bring to a boil; reduce heat, and simmer, mashing occasionally with a spoon or potato masher, until grape skins are loosened, 10 to 15 minutes. Stir in softened gelatin until dissolved.
3. Strain mixture through a fine-mesh sieve, pressing to extract as much liquid as possible (add water if necessary to yield 3 cups); discard solids. Divide mixture evenly among four serving glasses; refrigerate until set, at least 2 hours.
4. In a small bowl, stir together sour cream and honey; spoon over gelatins, dividing evenly, and spread gently to edges. Serve immediately or chill up to 2 days. Just before serving, garnish with halved grapes.

Note: Unflavored gelatin, an inexpensive thickener, can be used to make a number of no-bake desserts; to help the granules dissolve completely, gelatin needs to be softened briefly in cold water before being added to warm liquid.