Program Book - Master Brewers Association of the Americas

Award from the ASBC in 2005 with Mark Goldsmith, and the
Presidential Award from the MBAA in 2001 with Michael Lees. He
has worked on the executive boards of several professional bodies,
including currently the EBC. His current interests are in redox
control of staling in wine and beer, and the management of wine
fermentations in an age of climate warming.
P-80
Beer foam generation and its collapse description
JAN SAVEL (1), Petr Kosin (1), Adam Broz (1)
(1) Budweiser Budvar N.C., Ceske Budejovice, Czech Republic
Foam stability is a very important parameter for beer quality.
There are various methods available to measure it, but there is still
a requirement for a reliable and quick method of assessing foam
quality and stability. There are two ways of pouring or dispensing
beer from the bottle or keg. Both foams differ meaningfully having
different properties such as amount of foam, size distribution of
bubbles, foam appearance, including whiteness, texture and the
tendency to adhere to the glass wall (lacing or cling). The stability
of foam depends both on the kind of beer and foam formation. Foam
generation methods can comprise free fall of beer into glasses,
introduction of gas, shaking, mixing or beer passing through the
nozzle and powder or electrolytic release of carbon dioxide from
the saturated beer. Automated methods for the measurement of
beer foam collapse rate have also been described. There are two
methods generally used in many laboratories, the NIBEM method
and Lg-analyzer measurement. The third method formerly widely
used was the Ross Clark determination of foam stability. The new
instrument for beer foam stability measurement described in
this work was tested, and various models of beer foam decay were
assessed. The beer flowed under low (10–20 kPa) or high (200–300
kPa) pressure through a thin tube or nozzle into glass cylinder, and
the same beer was manually poured into the beer glass. Foam surface
fall was followed over the whole degradation curve. The sensor
movement was stopped 0.5 mm above beer level to avoid long time
measurement. The foam tester consisted of a needle conductivity
sensor controlled by a step motor, which enabled us to follow the
foam surface fall during its collapse. The measured data were
collected automatically through RS 232 and loaded into a computer.
The stirring method was also estimated, during which beer stirring
together with gas introduced into beer and beer intermediates was
used for foam generation. Quadratic, exponential and two-step
consecutive kinetic models were used for foam decay after foam
generation in these trials. The first two models provided a precise
description for nearly the whole foam degradation curve, but the
meaning of the parameters was well defined and understandable
only for the first part of the foam collapse. The third method gave
a reasonable description for the whole curve. The stirring method
describing fast beer collapse must involve both the foam generation
and degradation into decay equation. Examples of the beer,
production intermediates and model solutions containing foamactive
and foam-destroying compounds are presented and discussed.
Dr. Jan Savel was born in 1944 in Ceske Budejovice (Budweis),
Czech Republic. He studied at the Institute of Chemical Technology,
Prague, graduating in 1967 with a Ph.D. degree. Currently, Dr.
Savel is an external associate professor at the Institute of Chemical
Technology, Prague, as well as head of the Research Department at
Budejovicky Budvar Brewery, N.C., Czech Republic. Dr. Savel has
been a member of the EBC Brewing Science Group since 1994. He has
published more than 100 articles in Czech and foreign professional
magazines, as well as a monograph dealing with brewing
microbiology.
106
P-81
Fluorescence microplate readers as an alternative to flow
injection analysis for determination of wort β-glucan
MARK SCHMITT (1), Allen Budde (1)
(1) USDA Agricultural Research Service, Cereal Crops Research,
Madison, WI
Selection of new barley varieties to meet the needs of the malting
and brewing industry requires that the lines being developed meet
a set of malting quality standards that have been developed to help
maltsters and brewers predict the commercial performance of the
barley and resulting malt. One important parameter of the malting
quality determinations is the level of β-glucan found in wort, since
high wort β-glucan levels are thought to predict potential problems
with brewhouse filtration. Historically, malting quality assessments
have been made relatively late in the process of line development,
when sufficient grain is available to allow production and use of
the 55 grams of malt called for in the standard Congress wort
production method (ASBC Malt-4). Recently, a modification of
the Malt-4 method producing representative Congress worts with
significantly smaller amounts (