All forms of beverage alcohol, whether spirits, wine or beer, are initially based upon fermentation, which is the natural process of decomposition of organic materials containing carbohydrates. Fermentation occurs in nature whenever the two necessary ingredients, carbohydrate and yeast, are available. In making beer and wine, it is the most important part of the process.

Distilled spirits involve the extra step of distilling, which reduces the original water content and greatly increases the alcoholic strength. Where beers on average have an alcohol content ranging from 2% to 8% and wines from 8% to 14%, distilled spirits are usually in the range of 35% to 50% alcohol, although individual products may be either higher or lower.

The principle of distillation is based upon the different boiling points of alcohol (173.3*F) and water (212*F). If a liquid containing ethyl alcohol is heated to a temperature between these two points and the vapor coming off is condensed, the condensed vapor will have a higher alcohol concentration or strength. Some spirits types undergo more that one distillation in order to impart certain desired characteristics.

Because carbohydrates and yeast are found virtually wherever human life can be sustained, civilizations in almost every part of the world developed some type of beverage alcohol very early in their history. The Chinese were distilling a beverage from rice beer before 800 BC and arrack was distilled early on in the East Indies from sugarcane and rice. The Arabs developed a distillation method that was used to produce a distilled beverage from wine. A reference to distillation also appears in the work of the Greek philosopher Aristotle. The Romans apparently produced distilled beverages, although no references concerning them are found in writings before 100 AD. Production of distilled spirits was reported in Britain before the Roman conquest. Spain, France and the rest of Western Europe probably produced distilled spirits at an earlier date, but production was apparently limited until the 8^th century, after contact with the Arabs.

The first distilled spirits were made from sugar-based materials, primarily grapes and honey to make grape brandy and distilled mead, respectively. The earliest use of starchy grains to produce distilled spirits is not known, but their use certainly dates from the Middle Ages. Some government controls date from the 17^th century. As production methods improved and volume increased, the distilled spirits industry because an important source of revenue. As is still the case today, rigid controls were often imposed on both the production and sale of liquor.

The raw materials used for making a distilled spirit are of two basic types: those containing a high concentration of natural sugars and those containing other carbohydrates that can easily be converted to sugars by enzymes. Sugary materials include grapes, sugarcane, agave, molasses and sugar. Commonly used starchy materials include corn, rye, rice, barley, wheat and potatoes.

The earliest stills were composed of heated closed container, a condenser and receptacle to receive the condensate. These evolved into the pot still, which is still in use, particularly for making malt whiskey and some gins and brandies. The next refinement was heating alcohol-containing liquid in a column made up of a series of vaporization chambers stacked on top of one another. By the early 19^th century large scale continuous stills, very similar to those used today were operating in France and England. In 1831, an Irishman, Aeneas Coffey, designed such a still, which consisted of two columns in series.

Since distillation requires that the liquid portion of a fermentation mixture be vaporized, considerable heat must be applied to the process. The fuel used in distilling spirits has always been the most readily available at that particular time and place. Peat, coal and wood were the fuels used historically. The high steam requirement for continuous still operation inhibited the development of rectifying columns for production until after the Industrial Revolution.

The flavor profile of a pot still product is more complex than that of a continuous still product of the same alcohol content. This is a result of the different distillation methods.

The use of a continuous still results in a flavor profile that is more uniform than a pot still product. Many distilleries combine column and pot stills. The condensed distillate from the column still is fed to the doubler, a type of pot still heated by closed steam coils, and redistilled.

Aside from specific product categories such as whiskey, brandy or vodka, another method for classifying distilled spirits is as aged or unaged. Vodka, gin, neutral spirits and some types of rum and brandy are all unaged. Whiskies, cognacs and other products must be aged for specific periods (the minimums are usually mandated by law) in wooden barrels in order to develop specific characteristics of taste, color and aroma.

Most commonly, the barrels used for aging distilled spirits are made of oak, with various experts touting the benefits of American versus French oak. White oak is one of the few woods that can hold liquids while still allowing the process of breathing through the wood's pores. The pore size is such that small molecules such as water move through the wood more easily than larger molecules such as alcohol. This breathing process is caused by temperature and humidity differences between the liquid and the air in the warehouse. Some spirits are aged in new barrels and others in barrels that have been previously used for aging wine, sherry or other distilled spirits. In the course of aging, no one knows what happens inside the barrel, but distilled spirits producers have never found any substitute for time.

More information on the different types of distilled spirits products and their individual characteristics can be found on the following pages.