In the
alcoholic beverages industry, congeners (from French congénère, in turn from Latin com- “same” + genus “kind”) are substances, other than the desired type of
alcohol and
ethanol, produced during
fermentation. These substances include small amounts of chemicals such as
methanol and other alcohols (known as
fusel alcohols),
acetone,
acetaldehyde,
esters,
tannins, and
aldehydes (e.g.
furfural). Congeners are responsible for most of the
taste and
aroma of distilled alcoholic beverages, and contribute to the taste of non-distilled drinks.[1]Brandy,
rum and
red wine have the highest amount of congeners, while
vodka and beer have the least.
There is some evidence that high-congener drinks induce more severe
hangovers,[2][3] but the effect is not well studied and is still secondary to the total amount of ethanol consumed.[4]
Although
methanol is not produced in toxic amounts by fermentation of sugars from grain starches,[5] it is a major occurrence in
fruit spirits.[6] However, in modern times, reducing methanol with the absorption of a
molecular sieve is a practical method for production.[7]