here - the 34th European Brewery Convention

Three-dimensional structural analysis of kieselguhr particles and filter cakes
Katrin Mathmann 1 , Jonathan Schock 2 , Julia Herzen 2 , Franz Pfeiffer 2 , Heiko Briesen 1
1 Technische Universität München, Chair for Process Systems Engineering, Freising, Germany,
2 Technische Universität München, Physics Department (E17), Garching, Germany
Precoat filtration with kieselguhr is still the most frequently used method for the clarification of beer.
The process depends strongly on a large variety of variables. Therefore, the prediction of a particular
filtration run is very difficult. In order to understand the filter-cake formation and enhance predictability
at the same time, two aspects must be considered. These are the characterization of the kieselguhr
particles and the structure of the filter cake. A commercially available kieselguhr was characterized by
means of different microscopic techniques and micro-computed tomography. Against common
expectation it was observed that most particles are not plate or needle shaped but show a quite
regular spherical shape. The micro-computed tomography additionally allows the three-dimensional
visualization of the filter-cake structure. The goal of this study is to support brewers by regulating the
filtration process on the basis of intrinsic process knowledge.
P76
Impact of kieselguhr-free beer filtration on beer (flavour) stability - a field report
Thomas H Zimmermann 1 , JianJun Zhang 2 , Beatus Schehl 3 , Joerg Kress 3 , Huiping Li 4
1 BASF South East Asia Pte Ltd, Nutrition & Health, Singapore, Singapore, 2 BASF (China) Ltd,
Shanghai, China, 3 BASF SE, Lampertheim, Germany, 4 Guangzhou Zhujiang Brewery Co. Ltd,
Guangzhou, China
The authors will provide an update of the Chinese Brewing Industry and its consumption of disposable
filtration and stabilization aids. The industrial implementation of kieselguhr-free precoat-filtration and
stabilization at Chinese brewery Guangzhou Zhujiang Brewery (Nanning Plant) will be discussed.
To underpin the economical and sustainable effect of this regenerative filter and stabilizing aid, results
of an Eco-Efficiency Analysis, meanwhile evaluated and approved by China National Light Industry
Council, will partially be highlighted. Next authors will focus on overall impact on beer stability based
on chemical as well as sensory checks. Data of internal as well as external parties will be interpreted.
A further look into metal absorption from normally used kieselguhr vs. kieselguhr-free beer filtration will
be discussed; furthermore effect of residual metals such as iron will be introduced and based on field
report positive impact on beer flavour stability will be presented.
P77
Fine grinding and air classification of barley malt
Christian Nied 1 , Christian Esefeld 2 , Petra Först 1 , Karl Sommer 1
1 Technische Universität München, Chair of Process Engineering of Disperse Systems, Freising,
Germany, 2 Technische Universität München, Freising, Germany
Fine grinding of materials leads to significant changes of product properties, such as bulk density and
the flow properties. An increase of the specific surface due to grinding also increases the reaction rate
as well as dissolution processes. As could be shown by Tippmann for example, a fine milling of barley
malt results in slightly higher brewing yields. Since fine grinding in rotor impact mills causes a
significant rise of the product temperature, a spiral jet mill was chosen for comminution. The barley
malt was ground down to a particle size x 99,3 ≈ 50 µm and subsequently separated into a coarse and a
fine fraction using an air classifier. Due to classification, a protein rich fraction (also suspected to be an
enzyme rich fraction) and a starch rich fraction could be obtained as the starch granules were not
broken down. Using this grinding and classification process, developments of new customized
mashing technologies as well as for example high-fibre beverages should be possible.