Alcohol Distillation and the Art of Flavor Extraction
All spirits undergo two major processes – Fermentation and Distillation. During fermentation, yeast digest sugars into energy that is used by cells for fermenting alcohol into energy – creating a fermented liquid called fermentate which then is fermented again using yeast cells to produce alcohol (ethanol) as byproduct. Distillation then separates out the alcoholic vapors from water vapors using its lower boiling point of 212o F which allows alcohol molecules to vaporize while everything else remains liquid. These vapors can then be collected collected back together again into higher concentration of alcohol once condensed back together after distillation process is complete.
Alcohol-rich vapor known as the heart of the run should be drunk; all other vapors, known as heads and tails, should be discarded as they contain high concentrations of unpleasant-tasting congeners such as methanol (CH3OH), acetaldehyde (the cause of hangovers), or even paint thinner-scented acetone – which makes them dangerous to consume as they are not pure ethanol and should therefore not be drunk directly.
Heads and tails vapors can easily ignite or explode. Furthermore, they contain high concentrations of unwanted organic compounds with low boiling points that come off during distillation such as carboxylic acids, esters, and fatty acids that have unpleasant or toxic odours that do not belong in the final product.
Distillation begins by producing alcohol with a high percentage of ethanol and minimal contaminants, such as harmful congeners. Most distillers strive to reach this point. From there, they can add botanicals, herbs, fruit or other flavors using whatever recipe is called for by placing their desired item(s) inside an alcohol container and leaving it for some period.