Few works of the distiller's art can conjure up the kind of emotion and strong responses from its most faithful devotees as can Scotch, referred to in its homeland as acquavitae, the water of life.

Scotch is what it is and gives rise to the feelings it does because of what it represents - the very heart of the land from which it springs. Singlemalt whisky, during its yearly aging, the breathing of the cask, in and out, summer and winter, through expansion and contraction, takes on the characteristics of the local land and weather conditions. Even the ingredients and materials used to make the whisky - the barley malt, the wood or the peat, the copper pot still and the old, sherry-wood or bourbon casking - are made or harvested locally, and there is no Scotsman who will tell you that he cannot taste and smell the very breath of home when nosing his favorite whisky. For people away from their homeland, a singlemalt from their part of Scotland is home.

Because of that, the region of Scotland from which the malt was distilled is very important, and each region is presumably identifiable by its own distinct nose and flavor characteristics. Traditionally, the primary whisky types by regions are the Highland malts, characterized by a generally sweeter, smooth flavor (and further subcategorized, with the main subcategory being the Speyside malts); Lowland malts, which are drier and have a bit greater alcohol content (but with fewer individual differences in the region; Islay malts, which are the most identifiable because of their strong, peat-dried, nose, and their taste redolent of a cold, windswept outer Herbides shore with iodine and seaweed hints to the flavor; and Campbelltown, which are somewhat between the Lowlands and the Highlands in the level of sweetness, but having a distinct smoky foundation with substantial body and a slight salty tang.

Despite regional differences, all Scotch is produced by grinding a particular type of cereal grain or grains to a very coarse consistency - cracked instead of ground - and then moving that grain to a mash tun, where water, usually from a protected and often revered local source, is run through the grain at hot temperatures, much like the first step in making beer. The starches are extracted from the grain in this process. However, the issue here is not just any Scotch, but singlemalt Scotch. Single malt Scotch whiskey must be made only from malted barley. The barleys used to make singlemalts are grown in special fields set aside by the distilleries for their use. These barley hybrids are the result of generations of experimentation and breeding for a certain flavor, sugar yield (and thus higher alcohol content) and smoothness. Introduction of any other type of grain requires that the whiskey be categorized as a blend instead of a singlemalt.

The resultant liquid in the tun is then sifted through a lauder tun (and also, like the liquid in the beer making process, is called wort), is then cooled to between 22 and 24 degrees centigrade and run back into a separate container where yeast is added. Here, the solution ferments, and sugars in the wort are converted to alcohol. This is much like the first step in making beer.

The yeast is left in the solution for varying amounts of time, depending on the desires or traditions of the particular whisky maker or distillery. Once fermentation is completed, a strong ale called pot ale remains, which is about 9% alcohol by volume. This solution is distilled, which means that most of the water is removed and the alcohol content is concentrated, by heating it in copper stills. These stills are either continuous stills, called a Coffey still for grain whisky, or the solution is distilled twice in the case of singlemalt whisky using a pair of pot stills. Pot stills, used in most singlemalt distilleries, are onion or pear-shaped, with tall, slender necks designed to help the alcohol condense. The resulting liquor is cooled and put into casks. The Macallan, for example, is made solely from expensive, low-yield malted Golden Promise barley, and the distillery uses oaken sherry casks from Spain for aging its whiskey.

The furor over the minute details of a particular whisky aside, the specifics of making Scotch are not so exacting. In fact, distillers can point to three types of Scotch whisky: the malt whisky, which includes the singlemalts with which most people are familiar; various types of grain whisky and the blends.

Malt whisky is produced from one hundred per cent malted barley, and only from malted barley. Grain whisky is produced from a variety of cereal grains - rye, corn, and even rice - and the blend might or might not include malted barley. Blended whisky, typified by the Johnny Walker brand of Scotch, is a combination of malt and grain whisky mixed together in batches and placed in the same bottle.

Still, there are actual legal requirements that must be met before a beverage may be called Scotch. Whisky becomes Scotch only if it has aged in oak casks in Scotland for a bare minimum of three years. Another law requires that true Scotch must be 40% alcohol by volume. Contrary to some beliefs, there is no legal requirement for Scotch whisky to be bottled in Scotland; the requirements for designation as Scotch are met by the aging and alcohol strength specifications. The age of a Scotch whiskey as shown on the label is determined by the length of time it was aged in the cask, not by the date it was distilled. Thus, a Scotch purchased in the year 2000, but distilled and casked in 1950 and removed from the cask in 1962 is twelve-year-old, not fifty-year-old, Scotch. And there may, in fact, be some blending or marrying of other singlemalt batches made from the same distillery. Some batches may be 25 years old, some may be fifteen, some ten. The age shown on the label will be, by law, the youngest of those batches - if the youngest batch is ten years, then no matter that the rest of the marrying was all thirty years old: it is ten-year-old Scotch.

And aging is important. The longer a whiskey remains in cask, the more complex flavors it will acquire and the less spirit will remain (the remainder of the spirit, lost during aging, is referred to as the angel's share). Older Scotch is more expensive, of course. For example, one will pay upwards of $240 per bottle of the 25-year-old version of The Macallan, a so-called Speyside malt, meaning that the distillery is located near the banks of the Spey river in the Scottish Highlands. Typical twelve and fifteen-year-old bottles of singlemalt will range from $30.00 to $50.00 per bottle.

However, to complicate things further, keep in mind that the aging is done in oak casks, and that no one oak cask is like another. Whisky casks are made of oak: French oak, Spanish Oak, and American White Oak. Some distilleries will tell you which type of oak is used, and whether the wood was used in a previous casking (e.g., for sherry, or for bourbon). Other distillers remain silent on this subject, and that is somewhat surprising given the major role the cask will play in producing the ultimate product. Oak, as if you didn't know, is a natural commodity. One can therefore expect some differences in density, sap content and porosity. If that isn't enough to throw things off the track of uniformity, the wood is split by hand and the casks are made by hand. Therefore, you can expect each cask to be unique; there is no other one quite like it in size, in thickness, and even in the amount or size of its pores which will absorb and breathe out the spirit as it expands and contracts over the seasons. If it was previously used in a sherry cask, then some hints of the sherry it once held will remain in its pores and will be imparted to the spirit it will hold for the next ten, fifteen, twenty or thirty years.

When the aging is done, the marrying begins, except in the case of the oldest and finest singlemalts, which are made and bottled from single batches or casks. This single batch Scotch is considered the apex of the distiller's art, and the Scotch people will tell you that when drinking a single batch distillation, you are drinking their heritage. These are the batches which are most easily identifiable to a particular region by their nose or taste, and are generally the most expensive of all the singlemalts offered.

Whether you drink a Scotch to contemplate the beautiful Highlands or imagine a windswept Islay shore, or simply to experience the smooth heat, the malt sweetness and spicy smoke, knowing the ingredients, processes and history of Scotch whisky makes the drink much more enjoyable. Try it neat, in a small glass, and enjoy.