WhistlePig The Boss Hog XII Feather & Flame is a limited-edition, single-barrel Straight Rye Whiskey and the twelfth release in WhistlePig’s acclaimed Boss Hog collection. The rye is aged in new American oak and finished in distinctive Pulque Curado de Cacao barrels, bringing together earthy pulque character, cacao richness, and Mexican pepper spice. It is bottled at barrel strength, with proof varying by individual barrel.