Malt modification and its effects on the contributions of barley genotype to beer flavor

Based on prior research that showed significant genetic differences be- tween barley genotypes for beer sensor y descriptors, the effects of degree of malt modification on these descriptors were assessed in two experi- ments. The first experiment involved sensory assessment of nano-beers made from micromalts of Golden Promise, Full Pint, 34 doubled haploid progeny, and the check CDC Copeland. Average degree of modification was assessed by sampling grain from each of the 37 genotypes stored for three postharvest intervals prior to malting and brewing. The second ex- periment involved sensory assessment of pilot beers made from intention- ally under-, properly, and overmodified pilot malts of two barley varieties: Full Pint and CDC Copeland. In both experiments, genotypes were the principal sources of significant variati on in sensory descriptors. Degree of modification and genotype × modificati on interactions were also signifi- cant for some descriptors. Based on the results of this study, the genetic characterization of and selection for ba rley contributions to beer flavor are warranted, even with undermodified malts. The contribution of barley variety to beer flavor will likely be modest compared with the flavors developed during the malting process and the flavors contributed by hops and yeast. However, in certain beer styles, the contributions of barley genotype may be worth the attention of maltsters, brewers, and consumers.

We thank Seth Klann (Klann Family Farm) for the field experiment fa- cilities at Madras and Patricia Aron, John Andrews, Paul Kramer, and Xiang Yin (Rahr Malting Co.) for criti cal review of the manuscript. This research was supported and funded by the Flavor 7-pack of breweries (John Mallett, Bells Brewing; Veroni ca Vega, Deschutes Brewery; Mat- thew Brynildson, Firestone-Walker Br ewing Co.; Dan Carey, New Glarus Brewing Co.; Mike Gilford and Vinni e Cilurzo, Russian River Brewing Co.; Tom Nielsen, Sierra Nevada Brewing Co.; and Damian McConn, Summit Brewing Co.), the Brewers’ Association, the Gatsby Charitable Foundation, and the Spanish Ministry of Economy and Competitiveness (project AGL2015-69435-C3).