Hop flavoromics for distinctive beer

Hop is the spice of beer, as it provides unique flavour chemicals imparting taste (bitterness) and aroma. The continued release of novel hop cultivars with uniquely identifiable organoleptic characters is evidence that the flavour potential of hop has not been fully explored. Similarly, the genetic basis of hop organoleptic chemistry is relatively poorly understood. A mapping cross containing 166 genotypes (and the male and female parental plants) has been established into two replicated field trials (Tasmania and Victoria), separated by ~5° latitude. To date we have collected two years of data on survival, plant structure, flowering time, sexual phenotype, yield, and hop bitter acid chemistry contents on the male and female plants. Such data allow analysis of genetic variation and genotype-by-location interactions. However, the ultimate aim for the study is to obtain an extended chemical phenotype, including headspace solid phase micro extraction (SPME) of hop flavour volatiles, polyphenols, glycosides, laboratory scale beer volatile SPME profiles, and integrate this with organoleptic data. Successful completion of this hop flavoromics study will allow the identification of quantitative trait loci (QTL) in hop directly associated with beer organoleptic traits.