Sparkling Grapefruit Cocktail

Ingredients

• 1 large ruby red or pink grapefruit
• ¼ cup sugar
• 2 ounces gin (preferably Hendricks)
• ½ ounce fresh lemon juice
• 1 sprig tarragon
• 2 ounces French sparkling wine (such as Crémant de Bourgogne)
• Ruby red or pink grapefruit wedge (for serving)

Steps

1. Remove zest, along with some of the white pith, from grapefruit in wide strips with a vegetable peeler. Bring sugar and ¼ cup water to a boil in a small saucepan, swirling constantly, until sugar dissolves. Remove from heat and add grapefruit zest, pushing down to submerge. Let sit 30 minutes, then strain through a fine-mesh sieve into a measuring cup.
2. Combine gin, lemon juice, tarragon, and ½ ounce syrup in a cocktail shaker. Fill shaker with ice, cover, and shake vigorously until outside of shaker is very cold, about 20 seconds.
3. Strain cocktail into an old-fashioned or rocks glass filled with ice. Top with sparkling wine and garnish with grapefruit wedge.
4. Do Ahead: Syrup can be made 1 week ahead; cover and chill.