The Rhubarb Sour is a refreshing and tangy cocktail that combines the tartness of rhubarb with the sweetness of simple syrup and the zing of fresh lemon juice. This vibrant pink drink is perfect for summer gatherings or as a special treat any time of the year. The Rhubarb Sour is easy to make and can be garnished with a slice of lemon or a sprig of mint for an extra touch of elegance.