Orange-Campari Gelatin

Stir together orange juice, Campari, and sugar in a medium saucepan. Sprinkle with gelatin; let soften 1 minute.

Cook gelatin mixture over medium-low heat, stirring gently, until sugar and gelatin are dissolved, about 2 minutes. Pour mixture through a fine sieve into a stainless-steel bowl. Stir in Champagne and lemon juice; let stand 5 minutes.

Using a slotted spoon, skim foam from surface. Pour mixture into a 4 1/2-cup fluted gelatin mold. Refrigerate until firm, about 4 hours or overnight.

To serve, carefully set mold in a bowl of hot water for 5 seconds. Invert gelatin onto a serving platter.