Program Book - Master Brewers Association of the Americas

Poster Session: Brewhouse
Moderator: Vince Coonce, Miller Brewing Company, Milwaukee, WI
P-84
Development of new evaporation technology to improve flavor
stability
TOMOHISA ACHIOKU (1), Markus Herrmann (2), Werner Back (2)
(1) Asahi Breweries, Ltd., Production Department, Tokyo, Japan;
(2) TU München, Lehrstuhl für Technologie der Brauerei I, Freising-
Weihenstephan, Germany
Recently, it has been reported that lower thermal stress for the wort
improves the flavor stability of beer. As a result of development
of modern boiling systems in recent years, sufficient functions
can be performed even at shorter boiling times and with lower
total evaporation. These new boiling systems are very effective for
reducing thermal stress for the wort, but generally they require
an enormous investment. In this study, we investigated a new
evaporation technology with inert gas that can be installed easily
in existent boiling systems. It has been noted that blowing of inert
gas to wort can accelerate evaporation of aroma compounds, but
the optimum blowing conditions have not been fully studied. We
found that DMS was stripped off most efficiently when the boiling
process was split into two phases: boiling phase and stripping phase
with inert gas blowing. In this case, the improvement tendency
for flavor stability was found without any significant influence on
fermentation or beer quality. As a result of further research, we
found this effect could be obtained in the case of blowing into the
piping during transfer from wort kettle to whirlpool and stripping
at the whirlpool without the serious problem of hot break. This new
evaporation technology is very easy to install in existent boiling
systems and might be attractive especially for breweries which have
surplus carbon dioxide or nitrogen.
Tomohisa Achioku received a M.E. degree in chemistry and
biotechnology from the University of Tokyo in 1998 and joined Asahi
Breweries, Ltd. From 1998 to 2003, he worked as a member of the
technical staff for the Brewing Department in the Fukushima and
Ibaragi breweries. From 2003 to 2006, he worked for the Brewing
Section in Beijing Brewery Asahi, Ltd. in China. From 2006 to March
2008, he studied at TU Munich as a guest student.
108
P-85
Novel solution for the wort boiling process—Low cost
enhancement of wort boiling systems
TOMASZ BIWAŃSKI (1), Cornelia Rauh (1), Andreas Kasprzyk (1),
Antonio Delgado (1)
(1) Institute of Fluid Mechanics, Friedrich-Alexander University
Erlangen-Nuremberg, Erlangen, Germany
Both quality of beer and production costs depend on wort treatment
performance during the wort boiling process. Wort treatment
in systems with an internal evaporator implies flow induced
inhomogeneities and thus ineffective wort processing. Basing
on fluid mechanical research of the flow inside the wort boiling
kettle with an internal evaporator a subjet concept for the low cost
optimization of the system was developed. Herein, the deflector of
the boiler is placed under the wort surface. Hence, the wort enters
the annulus of the kettle horizontally under the liquid surface. The
main characteristics of the novel system consist of the elimination
of unwanted oscillations of the boiler during heating up and the
development of an enhanced, technologically adapted flow in the
kettle. In this work, the flow characteristic and physical phenomena
that occur during the heating up and boiling stage in standard
and subjet system configurations will be compared and presented
together with preliminary technological results for subjet boiling.
The experimental investigations were carried out in a one tube
natural circulation evaporator of industrial scale and a wort kettle
of 19 hl volume with a steam heated internal boiler. The flow in the
kettle was investigated experimentally by laser Doppler anemometry
and numerically by means of CFD. Technological investigations
were carried out with 12% extract wort. The heating up process
started with a temperature of 65°C, and the boiling process took
place at atmospheric pressure for 45 min with an evaporation
of 3%. The standard system revealed unsteady behavior during
the heating up phase. Severe flow unsteadiness (geysering) led
to increased fouling and consequently to shortening of the intercleaning
period. This phenomenon was not found in the subjet
system. Here, the heating up process was smooth, without flow
oscillations. Both numerical and experimental flow investigations
during boiling in the conventional system revealed the presence of
a significant short circuit flow in the kettle. Short circuit flows lead
to non-homogeneous wort treatment and increased energy demand.
In contrast, the short circuit did not occur in the subjet system.
Herein, increased momentum transport between the free jet and the
matrix fluid favored a homogenous flow arrangement. During wort
boiling, free DMS content decreased from 133 to 17 µg/l while the
TBZ-number increased by only 14 points. The results reveal that the
subjet realizes a homogenous, thermally and mechanically gentle
treatment of wort. The system is characterized by low evaporation,
low energy supply and elevated processing efficiency.
Tomasz Biwański received a M.S. degree in mechanical engineering
from Gdansk University of Technology, Poland. Since 2003 he has
actively participated in the development of systems and devices for
the brewing industry, especially in the field of wort boiling processes.
From 2003 to 2004 he was the scholarship holder of the Fleischmann
Foundation in the brewing discipline. From 2003 to 2006 he
worked as a scientific assistant at Technical University of Munich in
Freising-Weihenstephan. He is preparing a Ph.D. thesis concerning
thermo fluid dynamics of flows in high-volume reactors. Since 2006,
his Ph.D. work has been carried out at the Friedrich-Alexander
University Erlangen-Nuremberg in the Institute of Fluid Mechanics
(Professor Antonio Delgado).