Put simply, a still is a piece of equipment in which alcohol – whiskey, rum, vodka, gin, tequila, etc. – is distilled.
What is distillation?
Distillation is a process by which liquids are purified. In the case of alcohol, an already-fermented alcoholic substance is separated, using heat, into alcohol and water.
When fermented liquid is heated inside a still, the resulting vapor rises into a unique tube called a “swan’s neck.” This tube carries the vapor. Temperature in the sill is controlled so that only the vapor with the highest alcohol content will rise and end up in a water-cooled chamber, where the vapor cools, is reconstituted as liquid and drips into a collection chamber.
Most stills used in alcohol production are made from copper, stainless steel or brass. Copper is considered the ideal material for the job because of its consistent, even distribution of heat, which results in an even distillation.
Copper will also trap the unwanted sulfur compounds produced earlier – during an alcohol’s fermentation – that can make a liquid taste bitter.
Stills are handmade and usually designed according to a distillery’s unique requirements. The shape, size and makeup of a still affect their contents’ taste, so companies usually stick to one design for many years.