I quickly discovered that KBS is an over-the-top beer shored up with oodles of cold-brewed coffee, dark roasted malts, and earthy cocoa nibs. But unlike most stouts, it also boasts a hoppy bitterness that approaches that of an imperial IPA. In order to meld these seemingly at-odds flavors, the beer takes a year-long slumber in bourbon barrels stored in old gypsum mines that are carved below the streets of Grand Rapids. These caves maintain a crisp, cool temperature year-round, which allows the barrels to coax KBS into something utterly delicious: On the nose, KBS hits strong with coffee and faint whiffs of vanilla and bourbon; on the palate, though, it’s flat-out imposing with wave after wave of velvety chocolate, rich molasses, and dense vanilla oak. It’s as close to a masterpiece as beer can come and easily one of the most exquisite beers I’ve ever tasted.