How Low pH Can Intensify β-Damascenone and Dimethyl Trisulfide Production through Beer Aging

J. Inst. Brew. 116(1), 41-48, 2010During 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 compounds act as aroma compounds and not only as indicators.

Section: Methodsmentioning

confidence: 99%

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

Herrmann¹,

Klotzbücher

Wurzbacher

et al. 2010

“…However, more recently, it has been stated repeatedly that other flavours related to beer ageing, e.g. Strecker aldehydes 45,46 and β-damascenone ('cooked apple' or honey-like) 13,22,26 , may be equally or even more important for the overall unpleasant sensory perception of aged beer. Moreover, besides formation of staling volatile aldehyde compounds, a lot of other unwanted reactions e.g.…”

Section: Introductionmentioning

confidence: 99%

Flavour Instability of Pale Lager Beers: Determination of Analytical Markers in Relation to Sensory Ageing

Malfliet

Opstaele

Clippeleer

et al. 2008

125

Flavour changes of six Belgian pale lager beers were studied in order to estimate the importance of different parameters and reactions in relation to the ageing process. An attempt was made to link analytical data with sensory evaluation using multivariate statistical analysis. Partial least squares regression techniques (PLSR) were employed on the analytical and sensory data. As apparent from the PLSR model, significant indicators of lager beer ageing are aldehyde markers (especially total aldehydes, furfural, hexanal, 2-methylpropanal, 2-methylbutanal, and 3-methylbutanal), cold and permanent haze, and beer colour. Conversely, compounds or parameters that load negatively in the PLSR model for beer ageing are trans-isohumulones, cis-isohumulones, total bitterness, the T/C-ratio, polyphenolic markers (especially proanthocyanidins), the flavanoid content, and, to a lesser extent, the TB-index and reducing power (TRAP). The integrated analytical-sensorial methodology is proposed as a useful tool for evaluation of the flavour instability of pale lager beers.

“…Therefore it might be that a portion of these substances in second wort were transported to hydrophobic micropores in the A.C. and adsorbed by van der Waals force via hydrocarbon chains 12,28 , suppressing the production of deteriorative substances in beer, and leading to taste stability improvement. In particular, γ-nonanlacton was shown to increase during beer storage 7,8,31 . The fact that this substance was reduced to low levels in fresh beer (Fig.…”

Section: Influence Of Low Heat Load and Ac Treatment Of Second Wortmentioning

confidence: 98%

The Impact of Low Heat Load and Activated Carbon Treatment of Second Wort on Beer Taste and Flavour Stability

Yano

Back

Krottenthaler

2008

There is a vast repository of knowledge regarding improving beer taste stability via wort boiling. However, as far as we are aware, there are few reports dealing with taste stability improvement in terms of quality characteristics by boiling, under proper conditions, the first wort and second worts separately. In this study, more than 50 brews in a pilot scale brewing facility were conducted to investigate suitable boiling conditions for first and second worts. When the second wort (i.e., the last 10% of the total filtered wort) was kept under a low heat load atmosphere (78°C), casted to the boiling first wort, and then re-boiled for 10 min, the produced beer exhibited no significant differences compared to that of the general beer in terms of taste stability. However, when an adsorbent (bentonite, silica gel, activated carbon or PVPP) was individually added to the second wort and the same boiling procedure was performed, the oxidized flavour of the forced aged beer, treated with activated carbon, significantly decreased, compared to that of the general brew (level of significance α = 0.01). The data from the chemical analysis and fermentation behavior are presented.