Single barrel whiskey (or single cask whisky) is a premium class of whisky in which each bottle comes from an individual aging barrel, instead of being created by blending together the contents of various barrels to provide uniformity of color and taste. Even whiskeys that are not blends may be combined from more than one batch, or even from differing years to achieve their consistency. The whiskey from each barrel is bottled separately, with each bottle bearing the barrel number and in most cases the dates for the beginning and end of aging. Each barrel is thought to contribute unique characteristics to the finished whiskey. Recently, however, there has been some controversy over whether single cask whiskies are indeed all from single casks. Whiskies sold by Scottish distilleries such as Ben Nevis and especially GlenDronach as "single casks" have been revealed to be vattings of multiple barrels, which may themselves have been of different kinds, with the "single cask" designation referring only to the final cask of maturation. In the absence of specific regulation of this language it is not clear to what extent such practice is prevalent in the industry as a whole.