Fusel alcohols orfuselol, also sometimes calledfusel oils in Europe, are mixtures of severalhigher alcohols (those with more than two carbons, chieflyamyl alcohol) produced as aby-product ofalcoholic fermentation.[1] The wordFusel[ˈfuːzl̩] isGerman for "badliquor".[2]
Whether fusel alcohol contributes tohangover symptoms is a matter of scientific debate. A Japanese study in 2003 concluded that "the fusel oil in whisky had no effect on the ethanol-inducedemetic response" in theAsian house shrew. Additionally, consumption of fusel oils withethanol suppressed subjects' subsequenttaste aversion to alcohol, which suggested subjects' hangover symptoms were lessened, according to the journal.[3]
Fusel oil and fusel-oil acetates are used in thelacquer industry as high boiling pointsolvents.[4]
Excessive concentrations of some alcohols other than ethanol may cause off-flavors, sometimes described as "spicy", "hot", or "solvent-like". Some beverages, such asrum,whisky (especiallybourbon), incompletelyrectified vodka (e.g.siwucha) and traditionalales andciders, are expected to have relatively high concentrations of non-hazardous alcohols as part of their flavor profile. However, in other beverages, such asKorn,vodka andlagers, the presence of alcohols other than ethanol is considered afault.[5][failed verification]
The compounds involved are chiefly the following:[6]
Other higher alcohols that can be produced during fermentation include:
Duringdistillation, fusel alcohols are concentrated in the feints or "tails" at the end of the distillation run. They have an oily consistency, which is noticeable to the distiller, hence the other name "fusel oil". If desired, these heavier alcohols can be almost completely separated in areflux still. On the other hand,freeze distillation does not remove fusel alcohols.[citation needed]
Fusel alcohols can be reduced duringfermentation by lowering the fermenter's temperature or increasing the oxygen content.[7]
