Parallel brewing trials were performed in laboratory brewery. For beer wort hopping, hop pellets of diff erent age ("slightly aged" and "strongly aged" one) and storage indexes (0.35 and 0.59, respectively) were used. During brewing were measured bitterness, utilization of alpha-acids and index of alpha-acids isomerization. Mature beers were evaluated by panel taste testing. Th e results of panel testing, based on beer bitterness, drink ability and aroma, by universal fl exible system of product quality evaluation, showed no signifi cant diff erence between two beers. Th erefore it was concluded that old hop pellets with high hop storage index values (0.59) could be used for beer wort hopping when fresh hop supply is missing. However such solution needs prolonged wort boiling, more energy consumption and colour of hopped wort and final beer is more intensive.

Biotehnologija