A New Validation of Relevant Substances for the Evaluation of Beer Aging Depending on the Employed Boiling System

Markus Herrmann¹, Björn Klotzbücher², Michael Wurzbacher², Stefan Hanke², Udo Kattein², Werner Back², Thomas Becker² and Martin Krottenthaler²,*
¹ Rudolf Wild GmbH & Co. KG, Am Schlangengraben 3-5, 13597 Berlin, Germany.
² Technische Universität München, Center of Life and Food Sciences Weihenstephan, Lehrstuhl für Brau- und Getränketechnologie, Weihenstephaner Steig 20, 85354 Freising, Germany.
^*Corresponding author. E-mail: martin.krottenthaler@wzw.tum.de.

J. Inst. Brew. 116(1), 41–48, 2010 | VIEW ARTICLE

ABSTRACT
During the last years changes in aging indicators have been observed, supposedly resulting from modern brewing technology. The Research Brewery Weihenstephan (Forschungsbrauerei Weihenstephan) offers excellent opportunities for comparing different modern wort boiling systems under semi-industrial conditions. Employing three different boiling systems, nine brews were produced. The resulting worts were compared regarding the most common wort parameters. Furthermore the influence of the different boiling systems on aging indicators in the resulting beers was analyzed using a newly developed mass spectrometry-based method. The decrease in the total amount of aging indicators in industrial beers over the last years is very likely the result of lower thermal intake in modern brewhouse equipment. The total amount of aging indicators is sufficient to describe the differences in modern boiling systems. In summary, 2-furfural dominates all other indicators in terms of thermal influence. 2-Furfuryl ethyl ether can be suggested as good indicator of aging as postulated by Eichhorn, whereas β-damascenone is questionable as an aging indicator. Supplementary experiments were carried out to investigate the role of the aging indicators as stale flavour components. Because of synergistic effects, many stale flavour

Key words:
Aging indicators, beer flavour, boiling systems, brewhouse, synergistic effects, wort.