The carbohydrates used for making distilled spirits 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.
Among the most commonly used materials with high sugar contents are grapes, sugarcane, agave, molasses and not surprisingly, sugar itself. Starches that can easily be converted to sugars include grains such as corn, rye, rice, barley, wheat and potatoes.
After combining carbohydrates and yeast together in a liquid base and allowing it to ferment, the next step is distillation. The secret behind the distillation process is that the boiling points of alcohol (173.3°F) and water (212°F) are different.
When a liquid containing ethyl alcohol is heated to a temperature between these two points the alcohol vaporizes. This vapor is then captured and condensed; the condensate has a higher alcohol concentration than the original liquid. Some spirit types undergo more than one distillation in order to impart certain desired characteristics.