Session Chair:
Paul Lefebvre (Administrateur Brasserie Lefebvre, BE)
The impact of hop kilning temperature on the aromatic and biochemical properties of American hops
By Lindsey Rubottom, Oregon State University
American hop growers have historically dried hops in the range of 62-66°C using deep bed kilns (60 – 80 cm), but they have shifted to lower temperatures (52 – 57°C) in the last ten years, particularly for new American cultivars. With the sustained popularity of hop-forward beers featuring American hop varieties with high dry-hopping rates, lower temperature drying was hypothesized to preserve hop aroma volatiles and quality. Over four harvest years (2018-2021), six popular American hop varieties were evaluated to measure the impact of drying temperature on hop quality. Using a broad range of drying temperatures (52 – 72°C) at commercial hop farms, hop quality was evaluated via chemical, biochemical, hop grind sensory, and brewing measurements. While somewhat dependent on hop variety, the overall results indicate that aromatic hop chemistry and quality may not be dramatically impacted by kilning temperature. In contrast, hop enzyme activity is reduced at higher temperatures. These results suggest that growers may dry at higher temperatures without sacrificing aroma quality, thereby offering greater flexibility and throughput for the hop grower.
Exploring the Regional Identity of Hops in the Pacific Northwest: A Case Study involving Cascade and Mosaic Hops Grown in Oregon and Washington
By Michael Fechir et al., Oregon State University
This presentation examines the regional identity (terroir) of Cascade and Mosaic® hops grown in 2020 on 41 individual fields throughout the Willamette and Yakima valleys in the Pacific northwest USA. Hops were characterized chemically (hop acids, total oil and oil composition) and sensorially (projective mapping and check-all-that-apply). Multivariate statistical analyses revealed groupings that corresponded to regional (between states) and subregional (within states) locations. To substantiate these results, a subset of hop samples of each variety was used to brew 14 dry-hopped beers (IPA) on a 2.5 hL pilot scale to evaluate the extent to which regional differences were transferred to beer. A trained sensory panel was able to discriminate between beers brewed with the same hop variety based on regional and subregional differences. Additionally, soil chemistry & physical properties, weather & climate, and farm management practices were examined and some variables were identified as potential determinants of regional differences. These results offer initial evidence of hop differences that can be tied to subregional variation.
Reducing the environmental footprint of hoppy aroma by a novel yeast-based technology
By Simon Dusséaux et al., EvodiaBio
The contribution of hops in the environmental impact of brewing has long been neglected. Farming of hops generates up to 5 kg CO2e and requires >2700 liters of water per kg of hops, while it uses fertilizers and pesticides. EvodiaBio seeks to reduce the environmental impact of brewing by rethinking the way by which beer acquires its hoppy aroma. We have developed a natural and sustainable yeast fermentation technology to produce the key aroma molecules of hops. We use them to produce standardized and tailor-made natural aroma extracts that recreate the hoppy aroma experience more economically and with much lower environmental impact. These extracts can go beyond what is possible with hops, by allowing brewers to choose their favorite aromatic notes, while leaving out less desirable ones. This flexibility promotes fast creative development by allowing quick iterations on a single brew. Additionally, it can alleviate many challenges often encountered with hops, such as aroma inconsistency, limited supply, hop burn, hop creep, and waste management. We provide data that this technology is highly efficient in adding hoppy characteristics to non-alcoholic beer, while masking off-flavors
State of the art evidence that hop terroir affects beer flavor
By Ann Van Holle et al., Proefbrouwerij
Not only variety but also terroir may have a significant impact on the brewing characteristics of hops and, consequently, on the resulting beer flavour profiles. In contrast to extensive data on variety-specific effects available, profound insights into terroir influences are lacking. Therefore, the relevance of hop terroir was explored in detail by applying three industrially important hop varieties. Eight single-hop beers were produced with Amarillo, Cascade, and Centennial hops, originating from several geographical regions worldwide. Genetic and biochemical fingerprints of the various hop batches were generated according to the methodologies as described previously (1). The biochemical and sensory attributes of the corresponding single-hop beers were investigated to elucidate the consequences of terroir-driven variations in hop brewing features related to beer flavour. It was confirmed that terroir-related hop characteristics are key considerations for brewers to obtain high-quality beers with required and consistent flavour profiles.(1) Van Holle et al. (2019) J Agric Food Chem 67:3761-3771