D. C. SHARP (1), T. H. Shellhammer (1); (1) Oregon State University, Corvallis, OR, U.S.A.
Poster
For centuries brewers have used hops to impart hoppy aroma and flavor to
beer. Creative experimentation and the renaissance of craft brewing
over the past 30 years have increased the complexity of these hoppy
aromas. This increase, accomplished by sophisticated hopping regimes and
a diversity of new hop cultivars, has compounded the analytical
difficulty of understanding and controlling hop aroma in beer. Many
factors influence the final hop aroma properties of beer: hop variety,
dosage, and yeast interactions to name a few. This study focused on the
influence of these factors on the sensory properties of otherwise
identically brewed beer using descriptive sensory analysis techniques.
Twenty-one different beers were brewed by varying three factors in a
full factorial experimental design: hop cultivar (Simcoe, Hallertau
Mittelfrueh), timing of hop addition (60 min boil, 20 min whirlpool, 48
hr dry-hopping), and yeast (WL 1056 ale, WL 2124 lager, OSU2 wine) and
their requisite fermentation conditions. Three unhopped control beers
were brewed using each of the three yeasts mentioned above. Hops were
dosed at a constant mass of 1.5 g/L of wort/beer. This experimental
design allowed the contribution of each factor, along with their
interactions, to be described from a purely sensory perspective using a
trained panel. Not surprisingly, beers brewed with highly aromatic
Simcoe hops produced more intense and individually distinct aromas
depending on the hopping regime compared to the Hallertau Mittelfrueh
(HHA) hopped beers. Beers brewed with HHA hops showed less intense
aromas with less distinction between hopping regimes, except for the
dry-hopped treatment, which was characterized by a more floral aroma
than the other HHA treatments. Hop aroma was also affected by a hop
variety by yeast interaction, a hopping regime by yeast interaction, or
both. The ale yeast produced the most intense hop aromas, followed by
the lager yeast, and finally the wine yeast. It is likely that the
intense non–hop-derived aromas contributed by the POF+ wine yeast masked
the intensity of the aroma contributed by the different hop treatments,
suggesting that non–hop-derived contributions interfere with hoppy
aromas. This study is part of a multi-phased project that aims to relate
the sensory findings presented here to the analytical and instrumental
findings from subsequent studies to identify and quantify the factors
influencing hop aroma in beer.
Daniel Sharp is a Ph.D. student in the Food Science and Technology
Department at Oregon State University. His work is centered around hop
studies being conducted in Thomas Shellhammer’s lab. A native Oregonian,
Daniel earned a B.A. degree from the University of Oregon and his M.S.
degree from Oregon State University. He has presented hop aroma research
at the 2011 and 2012 Craft Brewer’s Conferences, 2011 MBAA Annual
Conference, 2012 World Brewing Congress, and 2012 Young Scientist
Symposium. Daniel is the 2012 recipient of the InBev Baillett-Latour
Brewing Scholarship to fund his Ph.D. work. His current research is
focused on developing a predictive model for hop aroma in finished beer.
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