fee brothers whiskey barrel-aged bitters 5oz fee brothers add these limited edition bitters to your next cocktail! fee brothers uses emptied oak whiskey barrels from tennessee to age these aromatic bitters. taste the difference of barrel-aged bitters. this premium bitters is strictly limited edition, bottled only once a year in the spring. don't miss out on the 2011 edition! in stock and ready to ship. features: limited edition. aged in oak whiskey barrels. unique flavor combination to enhance your cocktails. specs: capacity: 5 oz.