Trace Volatile Constituents of Beer Part I

Abstract

Fusel oil components found in beer include methanol, n‐propanol, isopropanol, n‐butanol, sec‐butanol, isobutanol, 2‐methyl butanol, 3‐methyl butanol, ethyl acetate, sec‐butyl acetate, isobutyl acetate and isoamyl acetate. A refined isolation procedure has allowed the recognition of a number of hop oil constituents in beer apart from those previously reported. In addition, several of the volatile substances which occur in beer have been shown to originate from malt and to occur in the essential oil of barley and malt husk. Hop oil, malt husk oil and identified fusel oil components together account for all but seven of fifty neutral steam‐volatile ether‐soluble constituents of beer so far detected.

The Chemistry of Hop Constituents

“…The components resolved by gas chromatography have been identified by retention data and, after recovery in a suitable trap, by physical techniques such as infrared and proton magnetic resonance spectroscopy and/or mass spectrometry. The advances in gas chromatographic technique over the past decade have led to the recognition of an increasing number of trace constituents in hop oil (146,147,221,222,321,323). The most refined technique used to date consists of gas chromatography using a high-resolution capillary column coupled directly to a time-of-flight mass spectrometer (74, [77][78][79].…”

“…To a group of Australian workers goes the distinction of being the first to demonstrate the occurrence of hop oil in beer (146,147). Starting with 400 1. of beer they obtained 57 g of neutral material soluble in ether which largely consisted of the higher alcohols and esters produced during fermentation.…”

A Study of the Fate of Volatile Hop Constituents in Beer

“…On the other hand, Harold et al (1960Harold et al ( , 1961 have reported finding about 1 ppm of the main hop components a University of California, Davis, California. b Employed by the U. S. Brewers Association.…”