Alcohol is produced by a small organism that can convert sugars in fruits into alcohol. This organism is called yeast. The process also produces carbon dioxide (the bubbles in beer or champagne). Alcohol can also be produced from grain (such as barley), but the starches in the grain must first be converted into sugars.
An alcohol concentration of 15 percent can be reached in the fermentation process. Higher percentages of alcohol will kill off the yeast.
To achieve higher concentrations of alcohol, the fermented liquid is heated to evaporate the alcohol. The vapours are collected and cooled to obtain a solution with a higher alcohol percentage. This process is called distillation.