Pop cork from champagne bottle 1 to 2 hours before using. Gradually pour champagne, allowing for foaming, into a 2-quart container; set aside.
Make a simple syrup: In a medium saucepan over medium heat, combine champagne, sugar, and water. Stir until the mixture just comes to a boil; reduce heat to low and simmer 5 minutes until all sugar is dissolved. Remove from heat, cover, and let stand approximately 10 minutes or until cool.
To the champagne, add the prepared sugar syrup, orange juice, and lemon juice (do not strain the pulp from juices); stir until thoroughly blended.
Ice Cream Maker - Transfer mixture to ice cream maker, process according to manufacturer's instructions.
Freezer Method - Pour into container, cover, and place mixture in the freezer. When it is semi-solid, mash it up with a fork and refreeze again. When frozen, place in a food processor or blender and process until smooth. Cover and refreeze until serving time.
Can be prepared 3 days in advance. Cover and keep frozen.
Makes 10 to 12 servings.
Champagne Citrus Sorbet Recipe: https://whatscookingamerica.net/sorbetchampagne2.htm