THE INFLUENCE OF THE AGE OF A HOP PLANT ON THE QUALITY OF HOP AROMAS IN BEER

Hops (Humulus lupulus L.) are one of the most important ingredients in beer in terms of taste and quality - providing bitterness, aroma and fullness. However, it is difficult to produce beer products with a consistent level of quality as hop quality may vary due to the climate, cultivation method, soil conditions, root condition, etc. The purpose of this study was to elucidate the influence of hop hop plant age on beer quality, especially on the aroma of beer. We examined differences in hop aroma by means of sensory evaluation and chemical analysis. In addition, in order to assess how the vegetative growth and reproductive growth of hops were dependent on hop plant age, the length of the vine and leaf size, stem diameter and flowering were monitored throughout the growing season. The hop samples used were selected from 8 hop gardens in the Saaz region during the 2010 and 2011 growing seasons. A comparison of vegetative growth, leaf size and stem diameter showed that hop plants that were younger (in terms of hop plant age) were larger and flowered later. In addition, the α-acid content was higher in the younger hops. As a result, significant differences in hop aroma characteristics were observed in beer made from the different hop samples. Based on these results, it was concluded that the more luxuriant vegetative growth and late flowering associated with the younger roots changed secondary metabolism, which also affected the generation of terpenes, thereby altering hop aroma quality in the beer produced. This information can help the brewers improve quality and design hop and beer products with a better aroma.