How Alcohol Works

What Is Alcohol?
Alcohol is available in a variety of forms, including wine, beer, liquor, whiskey and even moonshine. Henrik Sorensen/Getty Images

In order to understand alcohol's effects on the body, it is helpful to understand the nature of alcohol as a chemical, so let's take a look.

Here are several facts:

  • Alcohol is a clear liquid at room temperature.
  • Alcohol is less dense and evaporates at a lower temperature than water. (This property allows it to be distilled,by heating a water and alcohol mixture, the alcohol evaporates first).
  • Alcohol dissolves easily in water.
  • Alcohol is so flammable, it can be used as a fuel.

Alcohol can be made by three different methods:

  • Fermentation of fruit or grain mixtures. This is often followed by distillation of fermented fruit or grain mixtures (Spirits such as whiskey, rum, vodka and gin are distilled.)
  • Chemical modification of fossil fuels such as oil, natural gas or coal (industrial alcohol)
  • Chemical combination of hydrogen with carbon monoxide (methanol or wood alcohol)

The type of alcohol found in alcoholic beverages is ethyl alcohol or ethanol. The molecular structure of ethanol is C2H6O. It can also be written as CH3CH2OH or C2H5OH.

In this structure, C is carbon, H is hydrogen, O is oxygen. The OH (O-H) group on the molecule is what gives it the specific chemical properties of an alcohol. For the remainder of this article, when we say "alcohol," we mean ethanol.

You will not find pure alcohol in most drinks; drinking pure alcohol can be deadly because it only takes a few ounces of pure alcohol to quickly raise the blood alcohol level into the danger zone. For various types of beverages, the ethanol concentration (by volume) is as follows:

  • Beer= 4 to 6 percent (average of about 4.5 percent)
  • Wine= 7 to 15 percent (average of about 11 percent)
  • Champagne= 8 to 14 percent (average of about 12 percent)
  • Distilled spirits (e.g. rum, gin, vodka, whiskey)= 40 to 95 percent. Most of the typical spirits purchased in liquor stores are 40 percent alcohol. Some highly concentrated forms of rum and whiskey (75 to 90 percent) can be purchased in liquor stores. Some highly concentrated forms of whiskey (i.e. moonshine) can be made and/or purchased illegally.

In the United States, you must be 21 years or older to buy alcoholic beverages, and there are penalties for serving or selling alcoholic beverages to minors.