Ingredients
1 cup water
1 cup cane sugar
3 sprigs fresh rosemary
cane sugar and salt for the glass rim
1 1/2 ounces gin
1 ounce rosemary simple syrup
1 ounce grapefruit juice
1 ounce club soda

Directions
Heat water and sugar in a medium saucepan over medium-high heat. Stir until sugar dissolves then add rosemary sprigs. Once it reaches a rolling boil, lower to medium heat and let lightly boil for 5 minutes. Remove from heat and place a lid on the saucepan to let simple syrup continue to infuse for an additional 10 minutes. Strain into a clean glass jar or container and store in refrigerator for up to one week.
Decorate the rim of a high ball glass with cane sugar and salt, add ice and set aside.
In a shaker filled with ice, combine gin, rosemary simple syrup and grapefruit juice. Shake vigorously for at least a minute.
Strain into the sugar and salted glass filled with fresh ice. Top with club soda and garnish with a wedge of grapefruit and a sprig of rosemary.