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.

© SWA 1995