The Physics of Heat Transfer in Alcohol Distillation

Distillation involves heat transfer between heated fermented beverages such as washes and stills to create steam of alcohol molecules – this is because ethanol (the main component in alcohol) boils at lower temperatures than water (212o F). As this vapor rises through a still’s swan neck or lyne arm and condenses with its condenser, more concentrated molecules return back into liquid state, producing stronger alcohol concentrations each time until you end up with high proof spirits like vodka or whiskey!

Alcohol vapor does not consist solely of pure alcohol; rather it also contains other organic chemical compounds known as congeners that give spirits their distinct flavors. Congeners include alcohols, aldehydes, acids and esters that combine to form distinctive aromas for different spirits.

As the vapor moves up the column, it will encounter a mixture of condensed water and alcohol at its summit; this mixture is known as tails or heads. To separate tails from hearts containing pure ethanol without other compounds present, distillers often repeat distillation at different positions on their still.

Distillers rely on the difference in boiling points between liquid and vapor to adjust composition on an ongoing basis without incurring additional energy usage (other than what’s used to evaporate mixture). As illustrated by operating lines in Figure, by changing vapor-to-liquid ratio, distillers can move closer towards producing 100 percent ethanol.