Pot still distillation

A pot still has two parts: a pot in which the fermented wash is heated, and a head that catches the vapour and leads it to a condenser. Because alcohol and the aromatic compounds of the wash boil off together, the pot still separates them far less sharply than a column still, and that is why its spirit keeps more of the character of the raw material. Copper became the standard material for commercial pot stills in the seventeenth century; tall heads that increase reflux were a nineteenth-century development favoured in Scotland.

Each run is a batch. In the two-stage process described in the Irish Whiskey technical file, the first distillate (low wines) is distilled again; the first runnings (foreshots or heads) are set aside, the middle cut or heart is kept as new spirit, and the later feints are collected and redistilled with the next batch. In triple distillation a third run takes place in a spirit still and the cut is made there. The shape and size of the stills differ between distilleries and are one reason their spirits differ.

Single Malt Scotch Whisky must be distilled in pot stills at a single distillery from water and malted barley only. Irish pot still whiskey and Irish malt whiskey are pot-still spirits too; triple distillation is traditional in Ireland but not compulsory.