Alcohol Distillation and the Science of Aroma

Alcohol distillation is an intricate process requiring both precision and intuition. The primary goal is to extract ethanol from water while simultaneously extracting any congeners – molecules responsible for creating flavor in spirits – using evaporation, condensation and re-evaporation (reflux). Distillation involves an endless cycle of evaporation, condensation and refluxing that should maximize energy savings through sight gauge monitoring of water level, pressure, temperature and vapor flow.

Distillation columns consist of plates packed with material that absorbs water selectively from alcohol vapor. One advantage of this method is that it can be performed at lower temperatures, saving energy needed for heating purposes. Furthermore, using lower grade fuel allows companies to conserve fossil fuels while becoming more cost effective over time.

There is a common misunderstanding that when distilling liquid mixtures at given pressures, all components will have the same boiling point, allowing their vapors to collect separately and pure. Unfortunately, only a very small percentage will experience boiling points below atmospheric pressure – known as an “azeotrope”, and responsible for limiting alcohol concentration achievable via distillation. Under vacuum distillation processes however, this azeotrope disappears, and higher alcohol concentrations can be attained; however the cost associated with such systems significantly outstrip those associated with regular columns.