How Temperature Affects Alcohol Distillation

Temperature and Alcohol Distillation When alcohol passes from liquid to vapor phases during distillation, its concentration becomes greater than that in its source solution (see Figure 1). That means the ratio of water to alcohol vaporized state exceeds that found in its liquid state counterpart ( Figure 1).

Evaporation rate of the ethanol vapor can also be affected by its temperature of heating. Thus, for optimal results it is crucial that the wash be heated as gradually and smoothly as possible until its second critical moment, at around 78 degrees Celsius. Skilful balancing of heating rate must be achieved to avoid ejection of wash or blockages of connecting pipes due to “cake.”

Once temperatures reach approximately 65-68 degrees Celsius, light harmful fractions start evaporating, such as toxic methyl alcohol and acetaldehyde. At this point, a distinct alcoholic aroma begins wafting from the container as condensed liquid forms from which “heads” (collected for collection later) forms; eventually this becomes pervach.

Distillation allows distillers to selectively select and separate remaining fractions by exploiting their different properties – in this instance, boiling points – while their concentration corresponds with proof levels seen at the exit of the still.