While the distinctive single malts produced by individual distilleries are becoming increasingly popular, blending creates over 90% of the Scotch whisky enjoyed throughout the world.
By nosing samples in tulip-shaped glasses the blender selects from a wide palate - from the numerous Highland and Speyside malts to the strongly flavoured and peaty Island malts, and the softer and lighter Lowland malts. These malts are combined with grain whiskies - usually 60-80% grain whiskies to 20-40% malt whiskies, and are then left to 'marry' in casks before being bottled as one of the world-renowned blended whiskies.
A blend of a range of malt whiskies, with no grain whisky included, is known as a vatted malt.
The way we make Scotch whisky has evolved over several centuries, but the history of Scotch whisky embraces a much wider heritage; that of Scotland and its people.
What are the main kinds of Scotch Whisky?
There are two kinds of Scotch Whisky - Malt Whisky and Grain Whisky. The Malt Whiskies are divided into four groups according to the geographical location of the distilleries in which they are made, as follows:
(1) Lowland Malt Whiskies, made south of an imaginary line drawn from Dundee in the east to Greenock in the west.
(2) Highland Malt Whiskies, made north of that line.
(3) Speyside Malt Whiskies, from the valley of the River Spey. Although these whiskies come from within the area designated as Highland Malt Whiskies, the concentration of distilleries and the specific climatic conditions produce a whisky of an identifiable character and require a separate classification.
(4) Islay Malt Whiskies, from the island of Islay.
Each group has its own clearly defined characteristics, ranging from the lighter Lowland Malt Whiskies to those distilled on Islay which are generally regarded as the heaviest Malt Whiskies.
Malt Whiskies, which differ considerably in flavour according to the distillery from which they come, have a more pronounced bouquet and flavour than the Grain Whiskies. The production of Grain Whisky is not so influenced by geographical factors and it may be distilled anywhere in Scotland.
What gives Scotch Whisky its distinctive flavour and bouquet?
This is one of the mysteries of the industry and a secret which many imitators of Scotch Whisky have tried in vain to discover. Many theories and explanations have been put forward, but there is no universally accepted solution.
The distilling process itself is one factor. Scotch Whisky, after it has been distilled, contains not only ethyl alcohol and water but certain secondary constituents. The exact nature of these is not fully understood, but it is believed they include some of the essential oils from the malted barley and other cereals and substances that derive from the peat. The amount of these secondary constituents retained in the spirit depends upon the shape of the still and the way it is operated and also on the strength at which the spirit is drawn off. Grain Whisky, because of the process by which it is made, contains fewer secondary constituents than Malt Whisky and is accordingly milder in flavour and aroma.
The natural elements of water, peat and the Scottish climate all certainly have a profound effect on the flavour of Scotch Whisky. Water is probably the most important single factor and a source of good, soft water is essential to a distillery. Peat, which is used in the kiln or oven in which the malt is dried, also has an influence that can be detected in the ‘peaty’ or smoky flavour of many Scotch Whiskies.
The Scottish climate is extremely important, particularly when the whisky is maturing. At this stage the soft air permeates the casks and works on the whisky, eliminating harsher constituents to produce a mellow whisky.