Technical guidance: Stages of production: Distillation
Distillation involves the partial evaporation of an alcoholic liquid (the wash) followed by condensation of the vapour. The resulting condensate contains the more volatile components (including alcohol, which has a lower boiling point than water of78°C).
The method of distillation depends upon the type of spirit the distiller wishes to produce. Malt and fruit spirit are normally produced by batch distillation in large copper kettles known as pot stills. Grain and neutral spirits along with some fruit spirits are produced by continuous distillation in a ‘patent’ still (in the UK this is usually a still conforming to the ‘Coffey’ design). The two methods (Pot still distillation and Continuous distillation) are discussed in sections SPIR4100and SPIR4110.
Diagram of Pot Still distillation at SPIR4280.
Diagram of Coffey Patent Still Distilling process at SPIR4290.