Grapefruit-Thyme Cooler

1.5 oz gin

1.5 oz fresh grapefruit juice

¼ fresh lime

.5 oz thyme simple syrup  (see note)

Club soda

Thyme sprig for garnish

Note:   Make thyme simple syrup by combining equal parts sugar and water, heating until sugar melts, then adding fresh thyme leaves and allowing to steep for 1 hour.

Combine all ingredients except club soda and garnish in a cocktail shaker.  Shake over ice and strain into a tall, skinny Collins glass, a short tumbler, or a Mason jar filled with ice.  Top with club soda and garnish with thyme sprig.