Meghan Peltz (1), Thomas Shellhammer (2); (1) Sierra Nevada Brewing Co., Chico, CA, U.S.A.; (2) Oregon State University, Corvallis, OR, U.S.A.
Sensory
Poster
Only a fraction of the hundreds of chemical compounds found in hop
oil contribute to beer flavor. Best estimate thresholds of 10 hop
compounds were quantified in unhopped pale ale beer with ethanol
contents of 5% and 10% alcohol by volume using ASTM E679 threshold
methodology. While the solvating properties of ethanol had the potential
to impact solubility, this study concluded that variation in the
ethanol content had little effect on the sensory orthonasal aroma
detection thresholds of hop compounds in beer. Seven of the compounds
were not influenced by ethanol concentration. Ethanol had a
statistically significant effect on the threshold concentrations of
beta-damascenone (195 µg/L in 5% ABV to 74 µg/L in 10% ABV), but the
practical significance of the 36 ppb difference between the two ethanol
contents is uncertain. The threshold concentrations of geraniol and
linalool significantly increased when more ethanol was present, from 141
µg/L to 305 µg/L and 83 µg/L to 205 µg/L, respectively. The potential
ethanol suppression of terpene alcohols was relatively small, 2.5-fold,
and would likely have little impact on their odor activity values. The
results of this study can be used for OAV calculations across a wide
range of ethanol concentrations in beer.
Meghan Peltz is presenting the work of her master’s thesis from
Oregon State University, under the direction of Thomas Shellhammer,
specializing in the areas of sensory and hop chemistry. Post-graduation
Meghan was hired at Sierra Nevada Brewing Co. as a sensory manager
working with the Chico, CA, and Mills River, NC, breweries. Meghan
continues to be an active member of the ASBC Sensory Subcommittee and
MBAA in her new role. She is enjoying settling into the northern
California lifestyle, hiking and skiing in the Sierra mountain range on
the weekends.