Scotch whisky whisky used. An age statement on the bottle, in the form of a number, must reflect the age of the youngest whisky used to produce that product. A whisky with an age statement is known as guaranteed age whisky. Scotch whisky without an age statement may, by law, be as young as three years old. In the early 21st century, such "No age statement" whiskies became more common, as distilleries responded to the depletion of aged stocks caused by improved sales. Labels may also carry various declarations of filtration techniques or final maturation processes. A Scotch whisky labelled as "natural"
Single malt whisky not always clear what the term "single cask" refers to. At least some producers release vattings of multiple barrels that have been matured together for one final period in a larger single cask as "single cask" whisky. While cask-strength, or undiluted, whisky (sometimes having an alcohol content upwards of 60%) has recently become popular, the vast majority of whisky is diluted to its "bottling strength" - between 40% and 46% ABV - and bottled for sale. Whisky can be "chill filtered": chilled to precipitate out fatty acid esters and then filtered to remove them. Most whiskies are bottled this way,