Once the production method was very simple – a bag with barley was sunk in water, for example in a stream. Then, the barley was split in a dry place, so that it could sprout, and the grains were left for 10 days. The sprouting process was stopped by drying the barley on a peat hearth (it was the time when a peat was the main fuel source). Afterwards everything was thrown into a vessel with boiling water and distilling yeast to start a fermentation process. The blend was passed through a simple distillation device (alembic) twice and whisky flowed out on the other side of the device. First alembics were small and in order to cool and liquefy vapours people used ambient air. Only in the XVth century the advantages of cooling the radiator in containers with cold water were appreciated. Not before the middle of the XVIth century a pipe coil put inside the container was started being used.
Nowadays the whisky production process is much more complicated and consists of 5 major phases: distillation, maturation, fermentation, malting and grinding.