Phytochemical and sensory comparison of Czech and world flavour hop cultivars

Abstract

In the new millennium, a lot of hop flavour cultivars with a unique “varietal aroma” have been bred and widely used for a dry hopping of beers. Seven flavour hop cultivars were also registered in the Czech Republic in recent years. Essential oils, depending on their concentrations, combinations and threshold levels, are responsible for diverse aroma and flavours of hop cultivars in dry cones and beers. In this study, we evaluated qualitative essential oils parameters and sensory aroma profiles in dry cones of 7 Czech and 23 world flavour hop cultivars by multivariate principal component analysis (PCA), which divides cultivars to  uadrants. The Czech flavour cultivars Juno and Jupiter were placed in the first quadrant, influenced by higher geranyl Acetate and methyl-4-8-decadienoate contents. The Kazbek, Ceres, Eris, Pluto and Saturn cultivars were grouped in the second quadrant, influenced by higher 2-MeBu-isobutyrate and geranyl isobutyrate contents, in essential oils analyses. However, in sensory aroma analyses, the Jupiter cultivar was placed in the first quadrant due to its woody aroma, whereas the Juno and Pluto cultivars were placed in the second quadrant due to their floral and grassy aromas. The Saturn cultivar was placed in the third quadrant due to a fruity aroma and the Kazbek, Ceres and Eris cultivars were grouped in the fourth quadrant due to their citrusy aroma. 7 Czech and 11 world flavour hop cultivars were also compared by sensory aroma analyses in dry hopping brewing tests. There was no correlation found between cultivar sensory aroma profiles in dry cones and beers, and differences and discrepancies in flavours for all of them. We proved that Czech hop flavour cultivars provided original sensory aroma profiles in beers and that they are useful for breweries in different beer styles.