Mother Nature's greatest gift: Distillation

Although Mother Nature can be credited as the inspiration for distillation, adventurous alchemists developed the process. Interested in understanding the composition of matter (and in finding out how to turn it into gold), they boiled it to see what would happen. Once they learned how to capture steam, they had discovered distillation.

As distillation methods became more refined, farmers throughout the world used their crops to create the "water of life." The names of many of today's liquors, such as whiskey, eau-de-vie, aquavit, and vodka, evolved from this phrase.

The basic principles behind distillation are simple. The evaporation of water, its condensation into clouds, and the ensuing precipitation is an example of distillation. This process produces fossil fuels, drinking water, and alcoholic beverages. If you understand how a liquid turns into a vapor and back into a liquid again, you understand the basics of distillation.

Distillation separates substances based on their volatility. Two substances, such as water and ethyl alcohol, can only be separated if their boiling points differ by at least 1 degree Celsius. If their boiling points are too similar then the vaporized molecules will remain attached as they rise. This principle is responsible for certain alcohols having different properties (such as their different tastes and aromas).

Stills are used for distillation. The simplest still is a pressurized system containing a heat source, a tank to hold liquids, a hood or gooseneck tube to collect vapors, and a condenser, or container, where the vapor is turned into liquid. Some are as large as 30 feet high and 16 feet in diameter, while those designed for home use might only hold 5 gallons. Other equipment may be added to commercial stills to increase their efficiency.

Ethyl alcohol (the substance that makes you drunk) and carbon dioxide are produced during a chemical reaction called fermentation, which occurs when water, heat, sugar, and yeast are present. All fermentations - beer, cider, wine, and hard liquors - contain ethyl alcohol. The only difference is that hard liquor has been distilled to remove water, sugar, or other diluents. Hard liquor therefore has a higher percentage of alcohol per volume.

In beer and wine, trace elements of yeast and other organisms can sour the liquid. In the case of distilled spirits, however, once the liquor is bottled, it will not change over time. As a result of distillation, all living things - such as yeast and bacteria - have been removed, so liquor will not sour.

If you find a bottle of whiskey that your grandfather was hiding, it should taste the same as it would have the day it was bottled. The only true aging that distilled liquor goes through is in oak or large, stainless steel vats before it is bottled.