The impact of hop

26 Thirty-four commercial lager beers were analysed for their hop bitter acid, phenolic acid 27 and polyphenol contents. Based on analytical data, it was evident that the beers had 28 been produced using a range of different raw materials and hopping practices. Principal 29 Components Analysis was used to select a sub-set of 10 beers that contained diverse 30 concentrations of the analysed bitter compounds. These beers were appraised sensorially 31 to determine the impacts of varying hop acid and polyphenolic profiles on perceived 32 bitterness character. Beers high in polyphenol and hop acid contents were perceived as 33 having ‘harsh’ and ‘progressive’ bitterness, whilst beers that had evidently been 34 conventionally hopped were ‘sharp’ and ‘instant' in their bitterness. Beers containing 35 light-stable hop products (tetrahydro-iso--acids) were perceived as ‘diminishing’, 36 ‘rounded’ and ‘acidic’ in bitterness. The hopping strategy adopted by brewers impacts on 37 the nature, temporal profile and intensity of bitterness perception in beer. 38