Once cooled, it’s mojito time! Fill a highball or pint glass with cubed or crushed ice, and add 4 tablespoons of rhubarb syrup. You can muddle your mint right in the glass before adding the syrup and ice cubes, or muddle in separate container beforehand to add after these two ingredients. Then, add your white rum and give it a stir (optional if you are going for a mocktail).