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.
The term fusel is German for "bad liquor".
Composition and taste
The compounds involved are chiefly:
* 1-propanol
* 2-propanol
* butanol (various isomers)
* amyl alcohol
* furfural (not an alcohol)
Excessive concentrations of these fractions may cause off flavours, sometimes described as "spicy", "hot", or "solvent-like". Some beverages, such...