Presenter: Martin Zarnkow, Technische Universität München,
This project covers the following areas: sensory analysis of
beer and statistical evaluation of sensory test results. The aim
was to develop a model that is appropriate to compare different
sensory methodologies. The model is based on a modified
ranking method. Within this work, three panels performed
three difference tests. The stimuli in each test consisted of
pale lager with different amounts of diacetyl. First the panel
judges had to check the homogeneity for sensory materials.
This test combines a ranking test according to ISO 8587:2006
with an intensity measurement. Afterward the panels carried
out triangle tests according to ISO 4120:2004 and paired
comparison tests according to ISO 5495:2007. It could be
shown that a paired comparison test is more sensitive than a
triangle test. The ranking test seemed to be the most difficult
test in the case of finding differences between samples. Initial
weights and distributions of samples can be computed with
the model, and the boundary of two different samples can be
defined. In these, judges should be able to discriminate them.
The model can also be used to control a sample production for
sensory analysis. The function of the model was proofed and
validated. It can be used for each sample material. In addition
an assumption was made to describe the difficulty of difference
tests. In this way a comparison of tests is possible.
Martin Zarnkow apprenticed as a brewer and maltster
from 1989 to 1991 at a small brewery in Frankonia. Martin
graduated with a Dipl.-Ing. (FH) degree, with brewing
technology option, in 1996 from TU München Weihenstephan.
Martin then worked as a brewmaster for one year in a mediumsized
brewery in Germany. Since 1997 he has been the head of
the research group for beer and beverage technologies at the
Lehrstuhl für Brau- und Getränketechnologie (institute for beer
and beverage technology) at TU München in Weihenstephan. In
2010 his finished his external Ph.D. research at the University
College of Cork, Ireland, on the subject “Proso Millet
(Panicum miliaceum L.): A Sustainable Raw Material for the
Malting and Brewing Process."