This is useful in producing high quality alcoholic beverages, while ensuring that less desirable components (such as fusel alcohols) are returned to the primary flask.
en.wikipedia.org These substances include small amounts of chemicals such as other alcohols (known as fusel alcohols), acetone, acetaldehyde, esters, tannins, and aldehydes (e.g. propanol, furfural, glycols, ethyl acetate).
en.wikipedia.org It (along with similar fusel alcohols) is reputed to be responsible for severe hangovers, although experiments in animal models show no evidence for this.
en.wikipedia.org Whether fusel alcohol contributes or not to hangover symptoms is a matter of scientific debate.
en.wikipedia.org Today, some people use soda water synonymously with seltzer; other people use it synonymously with club soda.
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