Grapefruit juice with rosemary syrup

Preheat for the syrup in a saucepan 250 ml of water with the sugar and rosemary. Bring to the boil and let boil for about 20 minutes until a syrup.

Turn off the heat source, add the juice of 1 lemon and let it simmer for at least 2 hours while the syrup cools down.

Squeeze 1 grapefruit and pour the juice into a glass. Add rosemary syrup, sparkling water and ice cubes to taste.

Serve this drink with a sprig of rosemary.