Composition of Bitter Substances of Hops and Characteristics of Beer Bitterness. Masahiro Kowaka and Eiichi Kokubo, The Research Laboratories of Kirin Brewery Co., Ltd., 3 Miyahara-Cho, Takasaki, Gumma Pref., 370-12, Japan. J. Am. Soc. Brew. Chem. 35:0016, 1977.

On the basis of available information on the chemical nature of the bitter components of beer, a technique was established for evaluation of beer bitterness. A new concept, "the constitution of beer bitterness," was proposed for evaluating the quality and quantity of beer bitterness. This evaluation is based on both the contents of the bitter components of beer (measured by ion-exchange chromatography) and the bitterness of the individual components (judged by the taste test). The bitterness of various domestic and imported beers was evaluated in this way. Results showed that the bitterness intensity and characteristics of beers by reference to bitterness unit and the iso-α-acids content could be evaluated from the constitution of beer bitterness. The freshness of hops and beer and the type of bittering agent used could also be assessed in this way.

Keywords: Bittering agent, Evaluation, Ion-exchange chromatography, Iso-α-acids, Oxidation products.