Scotch whisky
Scotch is the name for the whisky made in Scotland (so-spelled there, rather than "whiskey"). Whisky has been produced in Scotland for a long time, sometimes illegally. The name is a transformation of the word usquebaugh, itself a transformation of the Scots Gaelic uisge beatha and Irish Gaelic uisce beatha, literally meaning the "water of life".
Scotland is divided into a number of regions that produce whiskies with different regional characteristics: Highland, Lowland, Speyside, Islay, and Campbeltown. These characteristics are described by words like smoky, peaty, seaweedy, etc.
There are two different distilling methods used to create Scotch whisky: grain distilling and malt distilling. These two processes are essentially similar, with malted barley used in malt distilling. Typically, the grain whisky is considered to be coarser than a fine malt whisky and therefore is used as part of blended whiskies. First some of the starch in the grain must be converted to sugar. This is done by malting, or for grain distilling, by mashing with water and adding an enzyme. Then yeast is added, to convert the sugar to alcohol. Finally the product is distilled to concentrate the alcohol and flavour. Scotch wisky is normally distilled twice to around 130 or 140 proof, then diluted with water to less than 100 proof before bottling.
Once distilled, the product must be left to mature in old Sherry or Bourbon casks for at least 3 years to be called Scotch whisky, although most single (unblended) malts are offered at a minimum of 8 years of age. The older the whisky, the better the flavour although they tend to level off after 25 years or so.
Colour is usually a good clue to the provenance and type of whisky. Old, sherried, whisky is usually v. dark in colour - think CocaCola. Old, un-sherried, whisky is usually a golden-yellow/honey colour. Some whiskies can be almost clear, even after 10 years and more in wood. The late 1990's saw a trend towards fancy 'wood finishes' - reracking whisky from one barrel into another of a different type to add the 'finish' from the second to the maturation effects of the first. The Scotch Malt Whisky Society bottling number 1.81 is known by some as "the green Glenfarclas": it was finished in a rum cask after 27 years in an oak (ex-Bourbon) barrel and is the colour of extra-virgin olive oil.
see also alcoholic beverage
With the exceptions of whisky and Scotch broth, a person or thing from Scotland is Scottish, not Scotch.