4 large fresh peaches – peeled, pitted, and sliced
1 cup hot water
1/2 cup light brown sugar
1 pinch ground cinnamon
2 1/2 cups dry white wine
1/2 cup triple sec liqueur
1 (750 milliliter) bottle sparkling white wine, chilled
Blend peaches, hot water, brown sugar, and cinnamon in a blender or food processor until smooth. Transfer to a pitcher; stir in dry white wine and triple sec. Cover and chill in refrigerator for at least 4 hours.
Strain peach mixture through a large cheesecloth-lined sieve; squeeze cloth to remove all the juices. Pour juice into a large pitcher; stir in sparkling white wine.