Amyl alcohol

The common name for pentanol, a five-carbon alcohol with a single hydroxyl group, and one of the higher alcohols formed during fermentation. At low concentrations these fusel alcohols add complexity to the flavour of beer, wine and spirits; at higher levels they turn harsh, contributing the rough edge and hangover character of poorly distilled spirits, where they concentrate in the fusel-oil fraction. Beyond beverages, amyl alcohol serves as a solvent and as the starting material for amyl acetate, the ester behind banana and pear flavourings. Distillers manage it through careful cut points during distillation.