Scotland's Whisky-Making Regions
What causes the taste difference between two brands of Scotch? The water used is a key factor, since distilleries that are almost next door to each other, yet employ separate sources of water, can produce Scotch with broad differences in taste. Other factors are: the experience of the distillery's staff and master blender; and any differences in the equipment used, such as the capacity and shape of the stills themselves.
That being said, Scotland is divided into distilling regions. From the taste alone, experts can identify whiskies produced in one region from those produced elsewhere. Lowland malt whiskies are produced in distilleries located south of an east-west dividing line running from Greenock to Dundee, while Highland malt whiskies hail from north of the dividing line. Speyside malt whiskies are produced in the valley of the River Spey. Currently, more than half of the malt whisky distilleries in Scotland are located in the Spey River Valley. The last region, the source of Islay malt whiskies, covers the island of Islay.
Each region produces spirits with their own identifiable characteristics. For example, Lowland malt whiskies are considered to be lighter than those produced in the other regions, especially when compared with Islay malt whiskies, considered the heaviest of the lot.