The Chemistry Behind Alcohol Distillation

Alcohol Distillation

All spirits distilled from fermented liquid called a wash are produced using fermentation of cereal grains into beer-like fermented wash. As you heat this fermented wash, alcohol molecules evaporate and turn into vapor that rises up into the still. As it rises up into the still, its arm draws off into cool water coil and becomes condensed, condensing into liquid form which then flows out the arm down through its column column and down its column. A distiller needs to know when and at what point to stop cutting this outflow between still heads (heaviest portion) hearts (lighter portion), tails (least concentrated portion).

Separating compounds requires high energy expenditure, but more importantly it must be undertaken carefully to avoid contamination with unwanted chemicals such as acetaldehyde produced during fermentation or furfural, an aldehyde associated with bitter taste and hangovers. Both these unwanted components have their own boiling points that cling to those of ethanol molecules making separation in a still difficult.

Distillation under vacuum conditions overcomes this barrier to more efficiently reach higher concentrations of alcohol, but does require more energy than traditional distillation methods due to lower pressure reducing how quickly vapor can be condensed by either water or air cooling; consequently requiring higher reflux ratios to reach desired results.