Program Book - Master Brewers Association of the Americas

P-195
A new approach to sensory evaluation
KARL SOMMER (1), Jens Voigt (1), Hans Scheuren (1)
(1) Technische Universität München, Center of Life Sciences
Freising-Weihenstephan, Germany
Flavor is the significant criterion of evaluation in beer tasting,
which depends on many primary and secondary causes. This
includes desirable and un-desirable aromatic compounds, but
also haptic and physical issues like viscosity CO 2 -level and color.
Taste as a subjective matter is valued individually quite different.
Influences of process changes are difficult to evaluate. In order to
get representative and fast results, a new sensory test was developed,
which can be realized with reasonable resources, and takes statistical
methods into account. The relative number of test persons who can
detect a difference in change remains almost constant in a group and
more or less independent from external influences. Individual errors
follow statistic behavior and can be assessed if the number of tasters
is big enough. The significance of results from a smaller group of
experienced tasters in a sensory panel can be improved by increasing
the number of test persons even if they are less experienced. The
results of this work are based on differentiation trials with beers
with different concentrations of benzaldehyde as a typical off-flavor
aroma compound. In a group of inexperienced tasters, mainly young
food technology students, qualified differentiation showed high
conformance and significance. This test indicates that the method
with the incorporation of statistical methods can be used efficiently
for the evaluation of process changes and their effect on beer taste.
The developed functional coherence can be applied for economic
process optimization.
Professor Karl Sommer was in 1943 in Ludwigshafen, Germany.
He was student with Professor Hans Rumpf at the University of
Karlsruhe and finished his Ph.D. thesis on “Mechanical Aspects of
Chocolate Conching” in 1974. After attaining a doctor of science
degree on powder mixing and sampling and working in the industry
for six years, he began working in 1982 as a full professor at TU
Munich in Weihenstephan (Freising, Germany). His main field of
research includes all aspects of disperse systems, like grinding of
malt, separation of solids (lautering, whirlpool, filtration), and
creation of foam (gushing). A special field is research on dispense
systems, cleaning, and waste reduction by biogas production.
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P-196
New highly aromatic products and distillates from smoked
malt—Flavors and compounds
JENS VOIGT (1), Andreas Richter (2)
(1) Technische Universität München, Center of Life Sciences,
Freising-Weihenstephan, Germany; (2) Weyermann Specialty
Malting, Bamberg, Germany
The production of beers from smoked malt can vary in a wide
range of smoked malt additions. Based on Pilsner malt, different
percentages of Bamberg Rauch malt were added to achieve different
characteristics of smoked beer flavors. Two different fermentation
procedures with top and bottom-fermenting yeasts were investigated
with respect to the profile of aromatic compounds. The main target
was to optimize fermentation conditions like temperatures. All beers
were analyzed and tested sensorially. In a second trial series the
products were distilled in order to produce distillate products which
can be used as flavorings. The process of distilling was performed in
a column under various numbers of trays and flow rates and other
process parameters. The resulting distillates were characterized by
sensory and chromatographic methods. These can be used for the
flavoring of innovative alcoholic beverages. The main goal of the
trials is to optimize the process to get distillates with a well balanced
aroma profile between smoke and malt notes.
Jens Voigt received a diploma engineer (M.S. equivalent) degree in
brewing and beverage technology from TU München-Weihenstephan,
Germany, in 1985. He started his career with A. Steinecker GmbH,
Freising, as a technical engineer in brewhouse, fermentation, and
filtration equipment. He held positions in sales, production, and
management with Steinecker until 1995. From 1988 until 1992 he
studied for his Ph.D. degree in brewing technology on beer foam from
Weihenstephan (Professor Dr. Narziß). In 1996 he joined Doemens
Brewing School in Munich, Germany, as managing director. Later
he joined Heinrich Huppmann GmbH, Kitzingen, Germany, as key
account manager for brewery equipment and was managing director
of brewmaxx, software solutions for the brewing industry. Since
early 2004 he has been a research associate with Professor Karl
Sommer at Lehrstuhl für Maschinen- und Apparatekunde (Chair
for Mechanical Engineering & Process Technology) at the WZW
(Wissenschaftszentrum Weihenstephan) (Center of Life Science,
Weihenstephan), working on brewing process technology. He is a
member of the MBAA and IBD and the Editorial Board of the Journal
of the Institute of Brewing, London (JIB).