Program Book - Master Brewers Association of the Americas

P-145
The influence of non-starch polysaccharides on the filterability
of wort and beer
STEFAN KREISZ (1), Sten Aastrup (1), Claudio Visigalli (1), Niels
Elvig (1), Marcel Mischler (2), Jürg Obricht (2)
(1) Novozymes A/S, Copenhagen, Denmark; (2) Novozymes A/S,
Dittingen, Switzerland
Non-starch polysaccharides mainly β-glucan and arabinoxylan are
known to influence wort as well as beer viscosity and filterability.
Even if the total amount of water soluble arabinoxylan is higher than
the amount of soluble β-glucan, the research done so far has been
mainly focused on β-glucan. Several papers describe the behavior of
β-glucan in the malting and brewing process, including studies on
the influence of shear forces during the brewing process and possible
gel formation, respectively. It was obvious that the first generations
of exogenous enzymes to enhance the filterability of wort and beer
were mainly focused on thermostable β-glucanases which are able
to hydrolyze β-glucan released at mashing temperatures above 60°C
when malt β-glucanases are already inactivated. Another reason for
focusing on β-glucans was the relatively smooth ability to measure
the total amount of higher molecular β-glucan (>10,000 Da) in wort
and beer by staining with Calcofluor and fluorescence photometer
detection. The measurement of xylans is rather elaborate. For this
research a new straight-forward method to measure all high molecular
(and therefore wort and beer viscosity impacting) non-starch polysaccharides
has been implemented. The high molecular weight polysaccharides
have been separated by ethanol precipitation, and the
xylans have been measured by the determination of xylose after acidic
hydrolysis. The results show mainly two important results. First,
xylans do contribute to wort and beer viscosity, and their influence
on lauter performance as well as on filterability is measurable in the
laboratory as well as in industrial scale. Even if the malt is well modified
there are measurable benefits in filtration performance (7%) and
extract yield (0.8%) when hydrolyzing the residual high molecular
weight non-starch polysaccharides. If the malt is inhomogeneous or
undermodified, which is quite common when dealing with the barley
quality of the 2006 and 2007 harvests, the residual xylans can play
a very critical role in production constancy. Hydrolyzing only the
β-glucans will improve the filterability, especially when brewing with
undermodified malt higher amounts of residual xylans can provoke
weak filtration performances (–20%) and gel formation (blocking of
the filter). Secondly, successfully hydrolyzing xylans with exogenous
enzymes depends on the right choice of xylanases. Only enzymes
belonging to a special family of xylanases (so called family 10) which
are specific to the water soluble xylans are able to reduce viscosity to
the desired level. The results will show an overview of how β-glucan
as well as xylans contribute to wort and beer viscosity and filterability.
Their development was followed over the whole production process
in lab scale as well as in industrial scale. In addition their behavior
after intensive shearing in lab scale will be documented.
Dr. Stefan Kreisz studied brewing and beverage technology at
the Technischen Universität München-Weihenstephan, Germany
(1991–1997). He graduated as an engineer in 1997. From 1997
until 2002 he completed his Ph.D. thesis at the Institute for Brewing
Technology I in Weihenstephan, concerning the filterability of wort
and beer. From 2000 until 2002 he worked as a scientific employee
and assistant at the malt laboratory at the Institute for Brewing
Technology I. From 2002 until 2007 he was an assistant professor
and head of the malt laboratory. His main research interest has been
cereals, malting technology, and beer filtration. He also worked as
a consultant for malteries and breweries. Since May 2007 he has
worked as a research scientist for Novozymes A/S in the Department
for Brewing and Alcoholic Beverages in Copenhagen, Denmark.
P-146
Novel backwash technology for improved cost efficiencies in
beer filtration
CRIS LEMAY (1)
(1) Porex Filtration, Fairburn, GA
In order to achieve the necessary clarity in beer, it is critical that
yeast, protein, carbohydrate particles and other visible and subvisible
particles be removed. Removal of these suspended particles
is often accomplished by filter sheets that are assembled in plate and
frame filters and are pre-coated with a filter aid such a diatomaceous
earth. The plate and frame filter has been around for many decades
and is a workhorse for breweries around the world. They have a great
advantage in that they have minimum operating requirements;
however, they do require significant labor and time for set up, tear
down and cleaning. Utilizing a novel filter cartridge composed of
sintered porous plastic, it is possible to utilize the same filter aids,
thus achieving the same clarity as the plate and frame, but by using
a simple backwash step essentially eliminate the need to tear down,
and re-assemble. The backwash step typically requires less than 1
minute from shut down to start up, saving significant costs in labor
and lost production time. This unique polyethylene media can be
chemically sanitized and cleaned allowing for multiple uses before
it needs to be discarded, thus reducing acquisition, warehouse
requirements and disposal costs. The study evaluates the use of
several filter aids in conjunction with the sintered porous plastic
cartridge filter, optimizing the precoat loading and determining
backwash effectiveness.
Cris Lemay received a B.S. degree in biology, with a chemistry minor,
from Salisbury University in 1983 and did additional graduate
studies in genetics and cell biology at the University of CT. He joined
Porex in July 2005 and is responsible for sales, distribution, and
technical marketing in North and South America. He currently has
23 years in filtration and separation in the areas of research and
development, product management, and sales and marketing.
137