Program Book - Master Brewers Association of the Americas

Technical Session V: Finishing
Moderator: Fred Strachan, Sierra Nevada Brewing Company, Chico,
CA
Fred Strachan attended and completed the UC Davis master brewer’s
program and IOB exam in 1995. Upon completion of the program,
Fred began his brewing career in the Filtration Department at Sierra
Nevada Brewing Company. He has held various positions within the
department and most recently has taken on the position of supervisor
in the chemical and water process and systems area. Fred is currently
treasurer-elect of ASBC and serves on the Program and Craft
Brewer’s Committees. He is also a member of the MBAA and IOB.
O-16
Effects on the formation of crystalline silica phases during
fluxcalcination of kieselguhr
THOMAS SCHLEICHER (1), Dominik Antoni (1), Winfried Russ
(1), Quido Smejkal (2)
(1) Institute of Resource and Energy Technology, Technische
Universität, München, Freising, Germany; (2) Leibniz Institute for
Catalysis at the University of Rostock, Berlin, Germany
Kieselguhr is mainly composed of the skeletons of diatoms, a
unicellular aquatic plant related to algae. These skeletons consist
of opal-like, amorphous silica, containing small amounts of
microcrystalline structures. Kieselguhr is used worldwide for deep
bed filtration processes in the food and beverage industry. Due to
its excellent characteristics as high absorptive capacity, surface
area and chemical stability, alternative filter aids could not prevail.
Prior to using kieselguhr as a filter aid, the raw material must
undergo a conditioning process. Three types of kieselguhr have to
be differentiated: dried, calcined, and flux-calcined. Flux-calcined
kieselguhr is manufactured by treating the kieselguhr in a kiln at
1620°F–2200°F after adding an alkaline flux, generally sodium
carbonate. Porosity and specific surface area strongly decrease
and most of the amorphous SiO 2 is transformed into a crystalline
phase of SiO 2 called cristobalite. Crystalline phases of SiO 2 can
cause silicosis and are suspected to cause cancer. Therefore the
influence of fluxing agents on the formation of cristobalite during
the fluxcalcination of kieselguhr was investigated. Dried kieselguhr
was treated at temperatures between 1620°F and 2010°F after
adding either Na 2 CO 3 or K 2 CO 3 as a fluxing agent in concentrations
from 1.0 to 6.0 mass.-%. The duration of the heat treatment varied
from 1 h to 4 h. Amorphous and crystalline SiO 2 phases were
differentiated via X-ray diffractometry (XRD). Samples containing
sodium carbonate powder as fluxing agent showed the tendency
to form crystalline structures. Samples containing potassium ions
showed a significantly lower tendency to form crystalline structures.
Adding the fluxing agent as aqueous solution advanced this effect
due to the optimal distribution of potassium. Samples were fluxcalcined
in melting pots in a ceramic oven. Furthermore the Seitz
water value of the samples increased in contrast to the raw material.
Using Na 2 CO 3 the water value of the flux-calcined samples was
greater than using K 2 CO 3 as a fluxing agent. In contrast to the white
color of the samples treated with Na 2 CO 3 the color of the samples
treated with K 2 CO 3 was brown. At the moment the influence of other
fluxing agents such as NaCl, KCl, CaCO 3 , CaCl 2 , CaO, MgCl 2 and
MgO is examined in order to increase the water value and the degree
of whiteness of flux-calcined kieselguhr. Furthermore kieselguhr
will be fluxcalcined in a rotary kiln and in a circulating fluidized
bed reactor, in order to investigate the influence of the kiln design
on the formation of crystalline silica. Results will be given in the
presentation at WBC.
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Thomas Schleicher received his diploma engineer degree in
technology and biotechnology of food from the Technische
Universität München in 2005. From December 2005 to March
2007 he was employed at the Chair of Energy and Environmental
Technology of the Food Industry and worked in the field of renewable
fuels. Since the retirement of Professor Meyer-Pittroff in March 2007,
he has worked in the field of beverage filtration at the Institute of
Resource and Energy Technology, Technische Universität München.
In filtration, he specializes in processing diatomaceous earth.
O-17
Re-inventing depth filtration—Purifying the brewing process
ALFONS WITTE (1), Bob Spadafora (1)
(1) Begerow USA
Factors within the brewing process that can affect the quality of the
beer have been present since the first “mead” was made around 1700
BC and the first depth filter was engineered. For decades, minerals
found in depth filters were unavoidable. Using depth filtration,
brewers have had to contend with and control issues affecting the
brewing process such as mold, introduction of heavy metals like
iron, and inorganic materials, all of which can affect beer flavors.
By eliminating these factors one can “purify” the brewing process,
reduce the cost of filtration, participate in “being Green” and
ultimately produce a better beer. We will show the effect of heavy
metals in the brewing process and what effects they have on making
beer. Due to new technology we will demonstrate how eliminating
minerals can make the brewer’s job easier. And, we will show results
from industrial scale testing to prove that by re-designing depth
filtration the brewer can take a huge step in purifying the brewing
process.
Alfons Witte was born in 1966. Witte holds a degree in beverage
technology (1993). Witte as been employed with Begerow since 1997
and is the head of sales, brewing and mineral water.