BIRGIT SCHNITZENBAUMER (1), Roland Kerpes (1), Fritz Jacob (2), Elke K. Arendt (1)
(1) School of Food and Nutritional Sciences, National University of
Ireland, University College Cork, Cork, Ireland; (2) Forschungszentrum
Weihenstephan für Brau- und Lebensmittelqualität, Freising, Germany
The brewing industry is facing an ever-increasing challenge to become
more cost-effective, while at the same time maintaining or improving
product quality. Brewing with unmalted oats can reduce the costs of raw
materials. However, the replacement of malted barley with unmalted oats
can also adversely affect the quality and processability of mashes,
worts, and beers. In this study, brewing with unmalted oats (0–40%) and
malted barley was carried out in a 60-L pilot plant. The impact of
various levels of unmalted oats on mashing, lautering, and fermentation
performance was monitored in detail using standard analysis,
Lab-on-a-chip capillary electrophoresis for protein profiling, and a
rheometer to determine viscous characteristics. The quality of the final
beers was evaluated using standard methods according to EBC and MEBAK.
In general, the processability of mashes containing up to 40% unmalted
oats was comparable to that of the reference brew (100% barley malt)
despite their higher viscosities. However, the extract and free amino
nitrogen content of worts significantly decreased with increasing levels
of unmalted oats whereas their fatty acid content clearly increased.
The final beers exhibited lower foam stabilities but good sensory
properties.
Birgit Schnitzenbaumer did an apprenticeship as assistant tax
consultant and worked in this job before she studied brewing and
beverage technology at the Technical University of Munich in
Weihenstephan, Germany. During her studies, she completed several
internships in breweries and did her master’s thesis on the effect of
malting on the protein profile of proso millet (Panicum miliaceum L.)
at the School of Food and Nutritional Sciences of the University
College Cork, Ireland. Birgit graduated with a Dipl.-Ing. (M.S.) degree
in brewing and beverage technology in 2009 and started her Ph.D. project
on the application of novel and industrial enzymes when brewing with
unmalted cereals at the University College Cork in November 2009.
