Finishing and Stability Session
Stefan Hanke, Bitburger Braugruppe GmbH, 54634 Bitburg Germany
Co-author(s): Georg Stettner, Bitburger Braugruppe GmbH, Bitburg, Germany
ABSTRACT: Stabilization has a long history in beer
production. In former times, beer was stabilized by long storage in
wooden barrels. During this very traditional and unsystematic method
wood derived tannins and beer proteins reacted, and the resulting beer
showed a higher colloidal and taste stability. With industrialization of
brewing, wooden barrels disappeared, and filtration became a very
important step in brewing as distribution channels became more complex
and beer was shipped all around the world. Production of a brilliant,
clear, and stable beer is the major aim of end-filtration, aside from
the removal of yeast and turbidity after fermentation. Nowadays, for
these stabilization purposes, the use of silica gel and PVPP is widely
spread in the brewing industry. In recent times natural tannin based
stabilization aids also came into the market. For these trials a highly
purified high molecular weight hydrolyzable commercial tannic acid
product was used in-line before end-filtration. Different dosage levels
of tannins were applied to industrial brewed beer in semi-industrial
scale filtrations. Concentration up to 2 g/hL of tannins were applied
and compared to 35 g/hL of silica gel. The impact of these tannin
dosages on colloidal and flavor stability were evaluated. All analytics
were done according to international standards. It could be proofed that
tannins are suitable for beer stabilization. A dosage of 1 g/hL was as
efficient as the application of 35 g/hL of silica gel to increase the
colloidal stability compared to an unstabilized filtered beer. With an
increasing dosage level of tannins from 1 to 2 g/hL the colloidal
stability of the final beer could be improved significantly. The removal
of proteins was very specific to haze forming proteins because no
impact on foam stability could be seen in our trials. The trials also
showed that the concentrations of iron, aluminum, and vanadium in the
final beer were reduced significantly by using the tannin product. The
tannin treated beers came along with a higher antiradical potential
(measured by ESR, T600 value), which is good for analytical flavor
stability. The removal of the product was very good as no remaining
tannins could be detected in the final beer. Also no negative impact on
the taste and flavor stability of the fresh beers could be observed. The
fresh beers that were stabilized with 1 g/hL of tannins showed a trend
to a less lingering aftertaste (with the same analytical IBU) than the
silica gel stabilized fresh beers. Besides the quality issues,
economical and also ecological (lower filter waste because of lower
dosage) savings could be generated by a use of tannins as a
stabilization agent. Savings of up to 30% in stabilization costs could
be possible. In our trials we showed that a natural tannin based
stabilization agent is suitable to increase relevant quality parameters
and improves colloidal and analytical flavor stability of filtered beer.
Stefan
Hanke was born in 1980. From 1999 to 2004 he studied brewing science
and beverage technology at Munich Technical University (Weihenstephan),
graduating as an engineer with a Dipl.-Ing. degree. In 2010 he received a
Ph.D. degree for his research on the influence of hopping technology on
the harmony of beer. During his studies he worked for and received
practical training at different German brewing and malting companies.
Since 2004 he has been a scientific employee at the Lehrstuhl fuer
Technologie der Brauerei I, Freising-Weihenstephan, Germany (Prof.
Back). From 2006 to 2007 he headed the institute’s Small Scale and Pilot
Scale Brewery Department. From 2007 to 2010 he was responsible for the
HPLC and GC Laboratory of the Institute for Brewing and Beverage
Technology (Prof. Becker) in Weihenstephan. Since 2010 he has been the
head of the pilot plant of the Bitburg Brewing Group, Bitburg, Germany,
and responsible for R&D issues of affiliated breweries.
VIEW PRESENTATION 141
