Petr Kosin (1), Adam Broz (1), Jan Savel (1); (1) Budejovicky Budvar, N.C., Ceske Budejovice, Czech Republic
Sensory
Poster
Stability, considered as the time from filling to the breakdown of
quality, is easily defined from a microbiological or colloidal point of
view—either to the completion of lag-phase growth of contaminating
microorganisms, or respectively to exceeding haze over 2 EBC units.
Although several methods have been described for sensorial stability
evaluation, the generally accepted border between sufficient and
insufficient sensorial freshness has not been set. Some producers use a
prediction from the antioxidant capacity or various kinds of forcing
tests; less spread is an analysis of the content of aged beer
components. The drawback of prediction from antioxidant capacity is
insufficient differentiation of real antioxidants (compounds of which
oxidation does not change beer perceived quality, like SO2)
from other oxidizable components of beer (compounds of which oxidation
change beer perceived quality, like polyphenols, bitter acids, sugar
reductones or amino acids). A more straightforward attitude is sensorial
testing, which is usually performed as vertical (one batch through
time) or horizontal (more batches of a given age) study. The drawback of
vertical study is that results are valid only for a limited amount of
batches; the drawback of horizontal study is lack of information about
the course of aging. Our newly proposed method is a combination of
vertical and horizontal study. For the purpose of this study 200 batches
of the same beer brand were sensorially tested through aging. The
results were statically processed to show how big variation is among
batches and how fast pale lager is aging under defined conditions.
Optimal processing of the data and expression of the results seems to be
striped bar charts for multiple age of beer. Sensorial testing and
proper statistical data processing is the only method for determination
and monitoring of real sensorial stability
Petr Kosin received engineering (M.S. degree equivalent, 2006) and
doctoral (Ph.D., 2012) degrees in brewing and malting at the Institute
of Chemical Technology Prague, Faculty of Food and Biochemical
Technology, Department of Fermentation Chemistry and Bioengineering,
Prague, Czech Republic. He worked on both of his theses, “Application of
Modern Methods for Yeast Activity Control in Brewery” and “Consumer
Perception of Beer Qualitative Characteristics,” at Budweiser Budvar,
N.C. in Ceske Budejovice. He has been working in research and
development at Budweiser Budvar, N.C. since his graduation. He has been a
member of the EBC Brewing Science Group since 2011..
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