Sensory and Olfactometry Chemometrics as Valuable Tools for Assessing Hops’ Aroma Impact on Dry-Hopped Beers: A Study with Wild Portuguese Genotypes

Abstract

Sensory, olfactometry (using the sums of odour intensities for each class of compounds) and chemometric analyses were used to evaluate Portuguese wild hops’ sensory characteristics and the aroma that those hops impart to dry-hopped beer. CATA analysis and agglomerative hierarchical clustering was applied for the sensory characterization of 15 wild hops of Portuguese genotypes, clustering them in two groups: one more sulphurous, floral, and fruity, and another more earthy, resinous, floral, and non-citrus fruits. Two hops representative of each group were selected for the production of four dry-hopped beers using the same base beer style (Munich Helles). Beers were analysed by quantitative descriptive analyses and quantification of hop-derived key volatile compounds. Multivariate statistical treatment of the data was performed. Results indicate significant differences (p < 0.05) in fruity, resinous, earthy, floral, and sulphurous attributes of hops, but the dry-hopped beers only have a significant increase (p < 0.05) in fruity and spicy notes when compared with non-dry-hopped Munich-style Helles beer. Hop olfactometry explained the sensory perception that the 11 hops not used for brewing (employed as supplementary observations) are placed into the space of the odour-active compounds profile of the four hops selected for brewing. These 11 hop samples have more spiciness than fruitiness potential.

Phytochemical characterisation and aromatic potential for brewing of wild hops (Humulus lupulus L.) from Northern France: Towards a lead for local hop varieties

“…Among other terpenoids, alcohol monoterpenes (linalool, geraniol, β-citronellol, α-terpineol) and aldehyde monoterpenes (citral) provide floral and citrus notes to beer, respectively (Rettberg et al, 2018). By contrast, other fruity aroma can be attributed to the presence of some esters, such as red berries-like for ethyl-3-methylbutanoate, whereas aldehydes, such as hexanal, confer grassy fragrances to the beer (Machado et al, 2021). Perception of hop volatile compounds after brewing remains complex.…”

“…The beers were subjected to a sensory study in order to highlight the aromatic traits of these hops after brewing. Recently, Machado et al, (2021) have studied the aromatic qualities of wild hops on dry-hopped beers. Hong et al (2022) evaluated, using partial least-squares discriminant analysis, the link between chemical characteristics of cones and their influence in hop-tea or after brewing.…”

Image‐based evaluation of beers at an online Pint of Science festival using projective mapping, check‐all‐that‐apply, and acceptability

“…On the contrary, many studies, for example, (Craine et al, 2021; Hayward et al, 2019; Machado et al, 2021; Moss et al, 2022b), have combined CATA and acceptability, the latter technique also known as overall liking (Lazzari et al, 2022; Meilgaard et al, 1999).…”

“…To the best of our knowledge, this is the first work using rapid sensory profiling methods with beers in Spain. Previous works using CATA to evaluate beer: With five samples of craft beers and n = 95 consumers (Craine et al, 2021), with four samples of beers made with alternative ingredients and n = 98 consumers (Hayward et al, 2019), or with 11 samples of beers using Portuguese hops and n = 25 semi-trained assessors (Machado et al, 2021). Other works used projective mapping to evaluate beer: For nine samples of Danish beers and n = 17 consumers (Giacalone et al, 2013) or for eight samples of Australian and German beers with n = 32 consumers (Savidan & Morris, 2015).…”

Sensory discrimination of single hop beers by using sorting combined with profiling and intensity rating

“…Nowadays, there are numerous "dual-purpose" hop varieties (i.e., Amarillo, Citra, or Mosaic) which are characterized by having a high bitter acid content and high flavor potential (Kankolongo Cibaka et al, 2017;Rettberg et al, 2018). Different studies have evaluated the sensory profile of hop cones or hop essential oils (Eyres & Dufour, 2009;Hopfer et al, 2021;Van Opstaele et al, 2013) and their contribution to the sensory perception of beers from various perspectives (Machado et al, 2020(Machado et al, , 2021Peppard et al, 1988;Sanchez et al, 1992), for example, the impact of dry-hopping rate (Lafontaine & Shellhammer, 2018b) or the role of hops mixtures (Lafontaine & Shellhammer, 2018a). Some work went as far as the development of predictive models for specific sensory beer characteristics (Machado et al, 2020).…”