Fusel alcohol 666105 208689428 2008-04-28T04:51:02Z Michał Sobkowski 5315381 iw:pl {{Unreferenced|date=February 2008}} '''Fusel alcohols''', also sometimes called '''fusel oils''', or '''potato oil''' in Europe, are higher order (more than two carbons) [[alcohol]]s formed by [[Fermentation (biochemistry)|fermentation]] and present in [[cider]], [[mead]], [[beer]], [[wine]], and [[Distilled beverage|spirits]] to varying degrees. The term ''fusel'' is [[German language|German]] for “bad [[liquor]].” ==Composition and taste== The compounds involved are chiefly: * [[1-Propanol|1-propanol]] * [[Isopropyl alcohol|2-propanol]] * [[butanol]] (various isomers) * [[amyl alcohol]] * [[furfural]] Excessive concentrations of these fractions may cause off flavours, sometimes described as "spicy," "hot," or "solvent-like." Some beverages, such as [[whiskey]], [[Siwucha]] and traditional [[ale]]s and [[cider]]s, are expected to have relatively high concentrations of fusel alcohols as part of the flavour profile. In other beverages, such as [[vodka]] and [[lager]]s, the presence of fusel alcohols is considered a fault. Very high concentrations — usually caused by incompetent distillation — can cause acute illness, including [[headache]]s, [[nausea]], [[vomiting]], [[clinical depression]], or [[coma]]. Such a liquor may be referred to as ''rotgut''. ==Formation and removal== Fusel alcohols are formed when [[Fermentation (biochemistry)|fermentation]] occurs: * 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. [[Category:Alcohols]] [[Category:Flavors]] [[de:Fuselöle]] [[es:Aceite de fusel]] [[fr:Alcools de fusel]] [[it:Fuselöl]] [[ja:フーゼル油]] [[no:Fusel]] [[nn:Fusel]] [[pl:Niedogon]] [[ru:Сивушные масла]] [[sv:Finkeloljor]] [[tr:Füzel yağları]] [[uk:Сивушні масла]]