- 1 (2-inch) cinnamon stick
- 2 whole cloves
- 10 black peppercorns
- 2 (2- by 1-inch) strips fresh lemon zest
- 2 (2- by 1-inch) strips fresh orange zest
- 1/2 teaspoon unflavored gelatin (from one 1/4-oz envelope)
- 1 1/2 cups plus 1 tablespoon white grape juice
- 1 cup dry white wine
- 1/2 cup sugar
- Pinch of freshly grated nutmeg
- 1 teaspoon finely grated fresh lemon zest
- 2 cups mixed grapes, stemmed, seeded if necessary, and sliced (lengthwise or crosswise)
- Special equipment: a 5-inch square of cheesecloth; kitchen string
- Put cinnamon stick, cloves, peppercorns, and zest strips on cheesecloth and tie it closed.
- Sprinkle gelatin over 1 tablespoon grape juice in a small cup and let soften about 1 minute.
- Bring wine, remaining 1 1/2 cups white grape juice, sugar, nutmeg, and cheesecloth bag to a boil in a 1- to 2-quart saucepan, then remove from heat and add gelatin mixture, stirring with a metal spoon (see cooks' note, below) until dissolved.
- Transfer soup to a bowl and chill, covered, in a larger bowl of ice and cold water in the refrigerator for at least 8 hours.
- Just before serving, discard cheesecloth bag and add grated zest and grapes to soup.