Method

• 1.
  Put the Champagne bottle in the freezer 30 minutes before you start the recipe. This step ensures the bubbles will stay in the final jelly. In a small bowl, mix the gelatin with the water and let stand until softened, about 2 minutes. (If using gelatin sheets, put the sheets in a bowl, add cold water to cover, and let soak until floppy, 5 – 10 minutes.)
• 2.
  Open the Champagne and pour ½ cup (120 ml) into a small saucepan. Return the Champagne to the freezer if you can stand the bottle upright. If not, put the bottle in the fridge. Add the sugar to the saucepan, place over medium heat, and heat, stirring, until the sugar dissolves. Remove from the heat. Liquefy the powdered gelatin by setting the small bowl of gelatin in a larger bowl of hot water (or microwaving the gelatin on high for 5 seconds). Stir the softened gelatin into the Champagne mixture and stir until dissolved. Strain the mixture through a fine-mesh sieve into a bowl or pitcher and let cool to room temperature.
• 3.
  Add 2 cups (480 ml) of the chilled Champagne to the cooled gelatin mixture and stir well. If adding embellishments to the gelatin, pour half of the gelatin mixture into a 2 ½-cup (600-ml) mold and refrigerate until almost set, 30 – 45 minutes; arrange the embellishments on top, then add the remaining gelatin mixture. If serving the jelly without embellishments, pour all of the gelatin mixture into the mold. Cover the filled mold and refrigerate until fully set, at least 8 hours or up to 1 day. (If the time of day is right, you can sip the remaining Champagne.)
• 4.
  To serve, fill a bowl with hot water. Dip the bottom of the mold into the hot water for a few seconds to loosen the jelly from the mold, then unmold the jelly onto a serving plate. Garnish with the mint.