Influence of humidity on the quality of baled hops at grower
Czech University of Life Sciences Prague, Faculty of Engineering,Kamýcká 129, Praha 6 – Suchdol, Postcode 16521, Czech Republic;
Nowadays, in most of cases cured hops are pressed into square bales instead of roundbales. The specific weight of packaged hop is about 22% higher in the square bale and intensityof moistening of packaged hop is very important in this case. There is an increased risk ofdampening of hops in the square bale when the moistening intensity is too high. In the oppositecase is increased risk of destruction of hop cones due to low moistening intensity. The aim ofthis work was find out the influence of the intensity of moistening of hops before pressing intothe square bales on the development of humidity and quality of hops after pressing duringstorage at the grower. There were pressed square bales with humidity of hops from 9.2% to16.2%. The square bales with hop’s humidity 9–10% represented a dry variant, square baleswith hop’s humidity 11–12% represented an normal variant and square bales with hop’shumidity 13% and higher represented a wet variant. The square bales were stored on the firstfloor of the drying machine house at the grower. The range of storage temperature was from 7to 40 °C. All square bales were of the same condition. Humidity of the hops was monitoredduring 10 days. At the end of the measurement, there was carried out a laboratory analysis ofhops of all square bales. Samples were analysed for content of α – bitter acid and destruction ofhop cones. During storage, the humidity of wet variant dropped from 14.2 to 12.7% and thehumidity of dry variant increased from 9.37 to 11.1%. The destruction of hop cones was highestat dry variant (28%). On the contrary the lowest value was at normal variant (12.3%) and it isabout 43% less. However, the dependence of destruction of hop cones by humidity at asignificant level α = 0.05 has not been proven. There was no proven differences of content ofα – bitter acid between all three variants. The highest value 4.9% was at wet variant. We foundout a direct dependence of content of α – bitter acid on the humidity of hops in this case. Theresults of content of α – bitter and destruction of hop cones show that the best one was normalvariant with starting humidity from 11.2 to 11.6%.