Grapefruit Gin Fizz Cocktail with Rosemary Garnish

water

sugar

sprigs of fresh rosemary

freshly squeezed grapefruit juice

gin

Juice of 1 lime, freshly squeezed (about ¼ cup)

rosemary simple syrup

-ounces club soda, or flavored sparkling water (such as La Croix)

rosemary, for ganrish

sliced cucumber, for garnish (optional)