Rosemary and Concord Grape Soda

Stir all of the ingredients in a glass to combine, then fill the glass with ice and garnish.

Grape-Rosemary Syrup
1 lb. Concord grapes, to yield 2 cups fresh juice
2 cups granulated sugar
2 sprigs rosemary

Process the grapes in an electric juicer, then fine strain the juice, or purée in a food processor or blender and strain through cheesecloth. In a saucepan, bring the juice and sugar to a boil, stirring frequently. Add the rosemary to the mixture and reduce the heat to low; simmer for 15 minutes, then remove from heat and allow syrup to cool. Bottle and refrigerate for up to 10 days.