15 sprigs mint leaves, or more to taste
3 fluid ounces Scotch whiskey
1 fluid ounce simple syrup
1 fluid ounce grapefruit juice
crushed ice, as desired
Put mint leaves into a tall glass. Use a muddler to bruise the leaves and release their aroma. Pour Scotch whiskey, simple syrup, and grapefruit juice over the leaves; stir. Add enough ice to fill glass; stir.