With just a little mint syrup, this bourbon grapefruit cocktail is a playful variation on the classic Brown Derby.
Homemade Mint Simple Syrup: Combine sugar and water in a small saucepan over medium heat and bring to a gentle boil. Stir to dissolve the sugar. Turning the heat to low, add the mint leaves and cover the sauce pan, letting the mixture simmer gently for about 10 minutes. Remove the pan from heat, uncover, and let the mixture cool to room temperature. Strain the mint leaves out and funnel the syrup into a heat-safe jar or bottle. Store in the fridge and use withing six months.