Lafontaine, S.1, Shellhammer, T. H.1 and Hahn, C.1, (1)Oregon State University, Corvallis, OR, USA
Technical Session 6: Sensory
Tuesday, June 06, 2017
1:45–3:30 p.m.
Everglades Ballroom
The range of different nonvolatile constituents extracted from hops in highly hopped beers suggests that iso-alpha-acids may not be the sole contributor to bitterness of beer. This presentation presents results from the second phase of a research project focused on examining factors within the beer matrix that influence sensory bitterness perception in highly hopped beers. Over 130 commercial beers were evaluated using a combination of sensory and instrumental techniques. Chemical analysis consisted of the BU, hop acids via HPLC, total polyphenols via spectrophotometry, and alcohol content plus real extract via an Alcolyzer (ASBC Methods Beer 23a, 23e, 35, 4g). Sensory analysis was conducted in two phases. Phase one focused on evaluating a large number of commercial beers with a large (19 member) trained sensory panel. One sensory replication was completed with all beers, and three replications were completed with two beers serving as internal standards. Phase two focused on evaluating a smaller number of beers (30) with a smaller (10 member) trained sensory panel. Three sensory replications were completed with all thirty beers. Of the 30 beers, 13 of the beers evaluated in phase two were also evaluated in phase one to compare and anchor the two data sets. The overall bitterness intensity of the beers was rated using a 0–20 scale. This study confirmed the inadequacy of total iso-alpha-acid content as a complete measure of beer bitterness, and resulted in the proposal of a new model to predict sensory bitterness. This model reveals the drivers of sensory bitterness and is an improvement on the traditional bitterness unit for assessing total bitterness using all of the bitter compounds found in beer. BU prediction was also modeled. Both models revealed the importance of oxidized hop acids as drivers of both sensory bitterness and the BU measurement.
Christina Hahn is a graduate student at Oregon State University (OSU) pursuing a master’s degree as a member of Dr. Thomas Shellhammer’s Brewing Science Laboratory. Her research focuses on the sensory perception of beer flavor and its components. Christina graduated with a B.S. degree in food science and technology from OSU in 2015. During her time as an undergraduate student she was the lead brewer for OSU’s pilot research brewery. In addition to brewing at OSU she has interned for Boston Beer Company, Deschutes Brewery, and Beam Suntory.
