Fusel alcohol

Fusel alcohols, also sometimes called fusel oils, or potato oil in Europe, are higher-order alcohols (that is, alcohols with more than two carbon atoms) formed by fermentation and present in cider, mead, beer, wine, and spirits to varying degrees.^{[citation needed]}

The term fusel is German for "bad liquor".

Composition and taste

The compounds involved are chiefly:^{[citation needed]}

• 1-propanol
• 2-propanol
• butanol (various isomers)
• amyl alcohol (various isomers)
• furfural (not an alcohol)

Excessive concentrations of these fractions may cause off flavours, sometimes described as "spicy", "hot", or "solvent-like". Some beverages, such as whisky, Siwucha, and traditional ales and ciders, are expected to have relatively high concentrations of fusel alcohols as part of the flavour profile. In other beverages, such as Korn, vodka, and lagers, the presence of fusel alcohols is considered a fault.^{[citation needed]}

Formation and removal

Fusel alcohols are formed when fermentation occurs:^{[citation needed]}

• at higher temperatures
• at lower pH
• when yeast activity is limited by low nitrogen content

During distillation, fusel alcohols are concentrated in the "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 a reflux still. Freeze distillation, on the other hand, does not remove fusel alcohols.^{[citation needed]}

Health effects

There is a popular belief that fusel alcohol contributes to hangover symptoms. One study indicated that fusel alcohol has no more significant undesirable health effects (headache, nausea, etc.) than ethanol, the primary active ingredient in all alcoholic beverages. This study involved an animal model of hangover, and its significance in humans is unclear.

External links

•  Chisholm, Hugh, ed. (1911). "Fusel Oil". Encyclopædia Britannica (11th ed.). Cambridge University Press.