T. B. WICHMANN (1), L. B. Larsen (1); (1) DuPont Nutrition Biosciences ApS, Brabrand, Denmark
Poster
Diminished attenuation can be caused by two likely evils: low wort
fermentability or poor yeast performance. This can place brewers on the
wrong side of the attenuation’s black hole event horizon. Why? Either
the wort’s sugars fail to contain sufficient and/or appropriate
fermentable sugar types, or the yeast is in a poor state of health,
i.e., pitching rate, aeration, and nutrition levels can all conspire to
reduce yeast viability. Medium to high attenuation levels can be
attained by increasing the level of fermentable sugars, but at the risk
of changing the composition of the sugar profile and, in turn, adversely
affecting the yeast. Introduction of glycoamylases during mashing
converts more of the dextrins into simple sugars, thus increasing the
concentration of fermentable sugars and, thereby, increasing the real
degree of fermentation (RDF). Detailed dose response studies hinted that
“black holes” occur in curves, representing the RDF as a function of
enzyme dosage. Decreasing RDF values arose as a function of increased
dosages of glucoamylases. This decrease in RDF was observed only for
limited dosage intervals, as RDF values increased again at even further
dosage increase. Consequently, similar RDF values were attainable at two
radically different glucoamylase dosages, i.e., we escaped the event
horizon! Analysis of these similar, albeit different, wort samples
showed their sugar profiles to be significantly different. This leads to
the conclusion that RDF levels can be difficult to estimate solely
based on the wort sugar profile because the wort sugar profile is also a
key determinant of overall yeast performance. Different glucoamylase
products were tested in systems applying 100% malt and systems applying
high corn inclusions in combination with malt in order to assess the
performance of enzymes in relation to the capability of the yeast. This
presentation summarizes these studies and details how the composition of
fermentable sugar types, represented by the degree of polymerization
(DP1, DP2 and DP3) affects the achieved RDF level. The interaction
between enzyme functionality, wort sugar profile, and yeast performance
to achieve desired RDF levels is described.
Tove Bladt Wichmann received her M.S. degree in food science from
Copenhagen University in 1994. She began employment with Danish Crown
AmbA in 1994 and, during a three year period, was responsible for food
safety before transferring to the daughter company, Tulip International
A/S, where she worked with product development. Since 1999 Tove has been
employed with DuPont Nutrition Bioscience ApS (formerly Danisco) in
Brabrand, Denmark. From 1999 to 2007 she created new product solutions
for the fruit industry. From 2007 to 2008 she worked as a scientist in
the Industrial Bioscience Department, with a focus on enzyme assays and
enzyme product stability. The chance to pursue work with enzyme
solutions within the bakery area made her move back to the application
world in 2008. In 2009 the Brewing Application group was inaugurated,
and with her experience with enzymes and cereals, Tove was transferred
and began her brewing career. During 2009 and 2010 she completed Brewing
Modules 1 and 2 at the Scandinavian School of Brewing and during the
past five year period has been involved in the product development of
six enzyme solutions for the brewing industry, of which three are being
sold on the market.
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