Fill a wineglass half full with ice. Add Blackberry Gin, Simple Syrup, and lemon juice. Top with Lambrusco and club soda. Garnish with blackberries and/or a thyme sprig.
Blackberry Gin:
Combine 1 cup gin, 3/4 cup blackberries, and 1 sprig fresh thyme in a canning jar. Screw on lid and shake. Let stand in a cool, dark place for 1 to 3 days to infuse, shaking once or twice a day. Taste each day to determine desired flavor intensity. Strain over a small bowl. Discard solids and return to jar. Chill, covered, up to 3 months. (Makes 1 cup.)
Simple Syrup:
Heat 1/3 cup each water and sugar in a small saucepan over medium heat, stirring until sugar dissolves and mixture thickens, 3 to 5 minutes. Transfer to a canning jar. Chill, covered, for 1 hour, or up to 1 month. (Makes 1/2 cup.)