Last Friday’s Aperol experiments yielded a winner: the Bluegrass cocktail. I adapted it from a recipe found on Difford’s Guide, a voluminous yet easy-to-use online cocktail guide that allows you to search by ingredient. It turned up this drink, credited to Hayden Lambert at Merchant Hotel in Northern Ireland. Aperol combines nicely with Maker’s Mark, which has its own hint of citrus, and the cucumber makes it surprisingly refreshing. Enjoy! Recipe: peel and chop a 2-inch length of cucumber. Muddle cucumber in the base of a shaker. Add 1-1/2 ounces Maker’s Mark bourbon, 3/4 ounce Aperol, 3/4 teaspoon heavy simple syrup (Mix 2 tablespoons of sugar 1 with tablespoon hot water, stir until sugar dissolves and then allow to cool—you’ll have enough for a couple cocktails. Or, make a large batch and refrigerate until next time.), 1 dash Angostura bitters and 1 dash orange bitters. Fill shaker partway with ice; shake until chilled. Strain into a chilled martini glass. Garnish with a cucumber wheel.