An experimentally hopped sour ale fermented with dark red wine grapes Observers of yestercentury once doubted the existence of the Dark Swan, stating the fair-feathered fowl was the only color of its kind. Explorers eventually upended that theory, shocking the world and shining light on the Dark. This beer might just do the same. It’s a sour ale fermented with dark red wine grapes, giving it its uniquely deep and rich purple hue. Then it received the signature Lagunitas treatment with a healthy dose of experimental dry hops. This might just shock your taste buds!