The Shrubarb Cocktail

Combine rhubarb, ginger, vinegar, and sugar in a medium saucepan over medium-high heat. Cover and bring to a boil, then reduce heat to low. Cook, stirring occasionally, until rhubarb is completely broken down and strands are visible, 10–15 minutes.

Using a fine-mesh sieve or a colander lined with cheesecloth, strain mixture into a glass container. Let cool to room temperature, then chill.

Combine gin, lime juice, and 1 1/2 ounces reserved ginger-rhubarb shrub in a cocktail shaker. Fill shaker with ice and shake until outside of shaker is frosty, about 30 seconds. Strain into an ice-filled Collins-style glass, filling three-quarters full. Top off with club soda.