Distillation is a general separation technique for liquids with different boiling points or for the separation of liquids from solved substances. Distillation is based on the fact that the vapour of a boiling mixture will be richer in the components that have lower boiling points. By careful warming up the liquid with the lower boiling point changes first into the gaseous condition and can be liquefied in a radiator again and kept thus pure.
The basic principle of distilling, evaporation and condensation, was already well-known to Aristoteles (384 to 322 v.Chr.), who described the water circulation in nature. The only practical application in the antique was the demineralization of sea water. The Arabs use distillation already in the 8. Century for the production of parfum essences. First distillation equipments with radiator for the production of high-per cent alcohol are mentioned in writings of the medicine school of Salerno (1420).
The alcoholic solution received by fermentation contains max. 15 per cent alcohol. By means of distillation high per cent alcohol (agrarian alcohol, see also bioethanol) can be produced. However, the procedures are more complex, since alcohol and water form an azeotrope, whose boiling point lies underneath the alcohol, and also secondary ingredients (undesired congeners) must be separated.
The distillation process for the production of high per cent liquor is called "brand". The first brand supplies for instance alcohol of 85 per cent. The congeners are removed in the second brand (fine brand) by rectification.
The manufactury for the production of spirits is called distillery.