Blueberry Grapefruit Mocktail

What you need:  – Blueberry syrup – A grapefruit – Club soda – Fresh rosemary

Place a piece of rosemary in a cocktail shaker and muddle it slightly to break it up. 

Fill the shaker with ice. Add blueberry syrup and grapefruit juice. Shake well.

Strain into a glass filled with ice. Top with club soda.