Put blackberries and sage in a large cocktail shaker. Add 1 tbsp. water; mash well with a muddler or end of a wooden spoon.
Stir in sparkling water, cover, then strain into an ice-filled glass (for a clearer drink, pour through cheesecloth).
Servings 0
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.