WhistlePig Double Malt 18 Year Old Straight Rye Whiskey is a mouthful in both senses, and it's the oldest WP's release to date. This Rye Whiskey (79% rye, 15% malted rye, and 6% malted barley) spent full 18 years in the barrel and the result is a symphony of soft, floral rich and spicy flavors.