After the Millennium Malt which were released in 2000, is this 21 Years Old Bushmills, the oldest ever bottled. Although limited, this whiskey is regular available. 21 Years Old is aged in a combination of bourbon and sherry casks. After 21 years following a marriage of two years in madeira casks. The result is a rich and sophisticated sweet whiskey that is characteristic of the softness of the best Irish whiskeys.