Prepare the simple syrup. In a small saucepan over medium heat, combine the sugar and water. Bring to a boil, then remove from heat, stir in the 4 large sprigs fresh tarragon. Cover and let steep for 20 minutes. After steeping, strain and press syrup to remove tarragon. Chill until at least room temperature.

For a single drink, muddle 6 blackberries with the leaves of a sprig of fresh tarragon and ⅛ teaspoon lime juice.

Pour 2 ounces hibiscus tea and 1 ounce tarragon simple syrup over a glass filled with cocktail ice cups.

Strain and press the muddled blackberries through a fine mesh sieve over the hibiscus tea.

Top with 2-3 ounces sparkling water, to taste. Stir to thoroughly combine and garnish with fresh tarragon, if desired.

For a larger batch of six, combine the hibiscus tea and simple syrup in a pitcher. muddle the blackberries with tarragon and lime juice by hand or in a food processor, and strain and press it into the pitcher. Stir to combine. For each drink, serve 4 ounces of this mixture with 2-3 ounces sparkling water over ice.