Alcohol Distillation and Its Connection to Terpenes

Distillation is one of the oldest techniques for extracting alcohol’s liquid components, making distillation essential in creating spirits like gin, whisky and vodka. Furthermore, this process can also be enhanced with flavorings to produce liqueurs.

Ethanol has a very high boiling point, making it easy to separate it from water. Other less delicious and potentially harmful congeners with lower boiling points must be removed from the final spirit before being blended in, this process being known as distillation head removal or foreshot removal and are known as heads or foreshots and should be discarded as they contain unwanted aromas like methanol, acetaldehyde (responsible for hangovers), acetone and some desirable esters which impart fruity aromas into its formulation.

Distillers strive to capture ethanol while eliminating its associated “faints”, or minor impurities, by skillfully cutting their still’s outflow from heads to hearts – this requires careful timing, as the distiller needs to know when it is time to restart distillation – in order to achieve an ideal heart run with as much pure ethanol content as possible and minimal impurities or flaws. A successful cut results in heart runs that contain as much desired ethanol content with minimal impurities or “faints”.

To do this, they use a column still, which is basically a pot still with partitions or plates set into an ascending column. As the wash vapor rises from the bottom of the still it encounters each plate where heat compels molecules to condense; each plate being slightly cooler than its predecessor means heavier molecules condense further up while lighter ones condense closer to the top of the column.