Single Malt refers to a whiskey from a single distillery and which is distilled exclusively by fermenting malted barley. A single malt whiskey may be also a mixture of several barrels from the same distillery, to achieve constantly the same taste. It must be matured in oak casks in Scotland for a minimum of three years. Each distillery has a own unique style of production techniques and maturation. For bottling a single malt it is usually necessary a longer maturation, a common standard is over 10 years. Some high quality products can have a longer maturation, 20 years and more.
Under the Scottish and EU regulations, bottled whiskey should have an alcohol by volume (ABV) of at least 40%. Some distilleries take the initiative to raise the alcohol content to 43% in order to not risk that alcohol can not meet the 40% standard because pf some errors during packaging. In fact, the original whiskey from the barrel (depending on age), have an alcohol content that usually goes to 50% or even 65%. Therefore, whether it is 40% or 43%, before bottling, the whiskey is diluted with water.