In a Collins Glass: muddle syrup, mint, and grapes. Add crushed ice and bourbon. Top with soda if needed. STIR, STIR, STIR UNTILL GLASS IS FROSTED! Garnish with a bourbon soaked grape wrapped in a pressed mint leaf. Add a lemon twist.
I don't like cooking my simple syrup. Adding super refined sugar to cold water and letting it dissolve naturally works fine and actually produces a lighter, cleaner final 1:1 product.
*Soak the grape and mint garnishes in bourbon and insist they be eaten when the drink is done.
It's a julep.