HOP CHEMISTRY IN RELATION TO BREWING—A REVIEW

Abstract

The synthesis of hop components of brewing value—viz., essential oils and α and β acids—from fundamental structural units such as acetic acid and isoprene, is outlined. Quantitative relationships between essential oils and resin acids are shown to result from common steps in the synthetic pathways of the two classes of compound. Changes in α and β acids resulting from oxidation and from boiling are discussed. Bitter values obtained by adding hops on the basis of polarimetric analysis are contrasted with those found in beer bittered at a constant hop rate, and thin layer chromatography is shown to afford a reproducible means of analysing beer for different hop constituents. 1967 The Institute of Brewing & Distilling