Program Book - Master Brewers Association of the Americas

frequent line cleaning is recommended. However, no agreed
standards exist as to how often cleaning should be carried out. As
it is a time-consuming job and beer losses are associated, there is
a tendency to extend periods between cleaning cycles, potentially
negatively impacting the product. A number of new cleaning
solutions have emerged on the market over the last few years. These
consist of novel, physical processes such as ‘slush ice’ cleaning,
electromagnetic devices and automated line cleaning systems
and new chemical approaches such as activated ‘water’. BRI has a
simulated cellar/bar dispense system where we have been involved
in independently testing new developments for their effectiveness.
Karin Pawlowsky studied physics in Germany and obtained a M.S.
degree in molecular biotechnology from Leicester University. She
then worked in research in the Food Science Department at Leeds
University before joining BRI in 1998. Karin initially joined the
product quality team at BRI, later transferred to raw materials, and
then joined the process team to work in the area of molecular biology.
Since 2006 she has been responsible for the microbiology laboratory,
where a range of analysis are being carried out employing a number
of different techniques. In addition, Karin works closely with Stephen
Livens (head of microbiology) and is responsible for the management
of member and non-member projects within the area of dispense
hygiene, which is of increasing importance to the brewing industry.
O-3
Are plastic bottles ready to replace glass as a beer packaging?
ROLAND FOLZ (1)
(1) VLB-Berlin (Research and Teaching Institute for Brewing in
Berlin), Berlin, Germany
One of the main aspects that influences beer flavor stability is the
impact of oxygen. Packaging materials like glass or metal seem to be
nearly inert against the permeation of oxygen. Alongside the wellknown
advantages of PET there is the problem of plastic’s inherent
permeability to gases (focusing on O 2 and CO 2 ) that occurs along
the partial pressure gradient between the inside to the outside of
the package. To enhance the barrier properties of different plastic
materials (PET, PEN, PLA, etc.) different bottle systems (multilayer
techniques, internal and external coatings, blendings) were
developed and improved. The quality differences of these various
systems were evaluated through the measurement of permeation.
A new test method to measure the permeation through plastic
materials will be presented. The real time aging and oxygen-free
bottling used for this method imitates the filling and aging process
in praxis as closely as possible. The lecture contains a comparison
and evaluation of the latest development in barrier enhanced plastic
bottles and closures. It additionally gives an overview of how far the
industry has come today concerning the possibility of filling qualitybrands
in plastic bottles or plastic event packs of different plastic
materials without losing the flavor stability of the product.
Roland Folz attended completed an apprenticeship as a brewer and
maltster at the Beck’s brewery in Bremen, Germany. After working
another year for the Beck’s brewery, he started his studies in Berlin
and received a diploma engineer degree in brewing technology from
the Technical University, Berlin. After graduation, he was head of the
Technical Department/Production at the Preussen Pils brewery in
Pritzwalk, Germany, for two years. In October 2006, he returned to
VLB-Berlin as a consultant for brewing technology and now works
for the Engineering and Packaging Department as the specialist for
the Filling Department and PET topics.
O-4
A novel method for interlaboratory analysis of total package
oxygen
CARSTEN ZUFALL (1), Carolina Wehrmann (1), Carlos De Amorin
(1)
(1) Cervecería Polar, C. A., Caracas, Venezuela
The measurement of total package oxygen (TPO) is a standard
procedure in bottling. It provides fundamental information
for the prediction and improvement of beer flavor stability.
Today’s analytical standard procedure has been developed by
researchers from Cervecería Polar almost 25 years ago (1).
Sufficient repeatability and reproducibility are vital for any kind of
measurement. In the case of TPO, repeatability between different
laboratories remains an unsolved problem and poses a serious
threat to the significance of the analysis (2), especially in large
breweries with multi-plant operations. In this work, several different
approaches for the preparation of TPO samples were compared,
among them modifications of containers and different matrices. As
far as the containers are concerned, trials were focused on bottles
with pry-off crown corks. A selection of bottles according to their
volumetric capacity was necessary in order to minimize errors.
The central issue to be addressed was the method of introduction
of well-defined amounts of oxygen into the container. Best results
were obtained by the use of crown corks custom-fitted with a septum
from gas chromatography, allowing the injection of the desired
amount of air with a gas-tight precision syringe. Matrix effects
were evaluated by performing reproducibility and repeatability
analyses with different liquids in the sample containers. In the
case of water, several modes of preparation were examined,
namely degassed and carbonated water, water with stoichiometric
addition of antioxidant to eliminate dissolved oxygen, as well as
demineralized or distilled water. None of the preparations yielded a
satisfactory reproducibility of TPO measurements. Using beer as a
matrix, statistical distribution was significantly better. Preparations
assessed included fresh tunnel-pasteurized beer, pasteurized beer
aged at 28 or 60°C, and pasteurized beer from the brewery’s pilot
plant. Combining the most favorable conditions, an acceptable
reproducibility and repeatability of 22% was achieved. Based on
these findings an interlaboratory analysis model was designed which
consists of two different levels of air injection into the beer, thus
generating three concentrations of oxygen. This model has been
put into practical use at Cervecería Polar and its reproducibility and
repeatability is at 24%, thus within the category of “acceptable”.
This compares to an “unacceptable” 48% calculated from the data
presented by the ASBC subcommittee (2). References: 1) Vilachá, C.
and Uhlig, K., Brauwelt 124, 754-758, 1984; 2) ASBC, Report of the
Subcommittee on Method for Reference Standard for Total Package
Oxygen, J. ASBC 65, 238-240, 2007.
Carsten Zufall is corporate manager for quality, innovation and
development at Cervecería Polar, C. A., Caracas, Venezuela, leading
quality management, brewery-related research, and new product
design. He graduated in brewing science from the Berlin University
of Technology in 1990 and subsequently completed a Ph.D. (Dr.-
Ing.) degree. Following his postdoctoral lecture qualification, he was
awarded an associate professorship (Priv.-Doz.) in brewing science
in 2001. Carsten is a member of the EBC Brewing Science Group, the
EBC Executive Board, ASBC, MBAA, the German Brewmasters’ and
Maltmasters’ Association (DBMB), the VLB Alumni Association,
and the Cerveceros Latinoamericanos Association. His current
research activities include beer flavor stability, flavor chemistry,
sensory analysis, and environmental topics.
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