A trendy rhubarb shrub (or drinking vinegar) is laced with powdered cocoa to create the sweet and sour base for this refreshing spring cocktail. Serve it with nuts or canapés as a prelude to a meal, whether it’s chocolate-heavy or not.
1 1/2 cups coarsely chopped rhubarb (about 4 to 5 stalks)
1 1/4 cups champagne vinegar or white-wine vinegar
1 cup granulated sugar
3 tbsp sifted cocoa
1 cup water
1/2 ounce chocolate-rhubarb shrub
1 ounce gin
3 to 4 ounces club soda
2 dashes Peychaud bitters
1 or 2 rhubarb stalks for garnishing (optional)
To make the shrub, place rhubarb in a resealable container. Pour in vinegar, making sure rhubarb is submerged. Seal the container and let stand in a cool, dark place until rhubarb flavour infuses (3 to 4 days). Shake daily.
Once the vinegar is infused with rhubarb flavour, fine-strain the liquid through a coffee filter or several layers of cheesecloth into a bowl. Discard the chopped rhubarb. In a bowl, whisk sugar with cocoa until they’re evenly mixed. Place sugar-cocoa mixture in a small saucepan and whisk in water. Set over medium heat. Cook, stirring occasionally, until sugar dissolves (about 5 minutes). Remove from heat. Whisk in vinegar infusion. Let cool completely. If making ahead, rhubarb-cocoa shrub will keep covered and refrigerated for at least 2 weeks.
To prepare the garnish, use a vegetable peeler to pull thin strips from rhubarb. Place in a bowl filled with ice and water. Refrigerate until curly (about 30 minutes).
To prepare the cocktail, pour the shrub, gin and bitters into a tall chilled glass. Add ice, then top with club soda. Stir until mixed. Garnish the cocktail with rhubarb curls. Serve immediately with a spoon to stir.