What is the principle of liquor distillation?

The purpose of distillation is to use the different boiling points of various substances contained in fermented grains to evaporate volatile alcohol, water, miscellaneous ester oil and ester substances into gas and then cool them into liquid, so that 4-6% alcohol in fermented grains can be concentrated to 50-70%. Distillation can kill microorganisms in fermented grains and regenerate some flavor substances. In order to loosen fermented grains and facilitate distillation, a small amount of chaff is often added. But using too much bran will have a bad taste.

Generally, the alcohol concentration in the wine head is relatively high, and the boiling substances such as aldehydes, esters and ketones gather in the wine head, and the alcohol concentration drops sharply near the tail. Although fusel oil has a high boiling point, its evaporation coefficient is affected by alcohol content, mostly at the head and tail of wine.

Therefore, the distilled new wine heads often have a bad smell. But after long-term storage, because of the conversion of alcohols, the fragrance can be enhanced.