Alcohol distillation is an integral component of turning fermented liquids like beer, wine and other fermented drinks into whiskey, rum, brandies or other spirits. Distillation takes the sugars in raw materials and converts them to ethanol; while necessary for production purposes, distillation may leave behind undesirable and potentially harmful dissolved materials which may negatively impact health.

Distillation is an energy-intensive chemical process that uses heat energy to heat a mixture and boil off excess water, in order to separate alcohol and unwanted elements (called congeners ). Ethanol (drinking alcohol) has a very high boiling point and so quickly separates from its congeners; other alcohols like Acetaldehyde tend to stick together in the still and produce hangovers, with its unpleasant aroma being an even bigger factor than its lower boiling point; other harmful compounds such as Ethyl Carbamate and hydrocyanic acid should also be eliminated as they contain potentially dangerous components that need removing in order for full extraction to occur.

Manufacturers must exercise great care when increasing the temperature in a still. Increases must be gradual so as not to eliminate desirable ingredients while at the same time getting rid of unwanted elements that could otherwise be present; hence why commercial units often utilize preheating systems.

Home distillers may not always be careful when it comes to copper concentration levels in their product, which was evidenced in our samples. Some sources pointed to poor or careless distilling while other factors could include raw material used for making the mash or the age of their still. Furthermore, some home distilled spirit contained lead which should be avoided.