Analysis of Hop Drying in Chamber Dryer
Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Agricultural Machines, Kamýcká 129, CZ165 00 Praha 6 – Suchdol, Czech Republic
*Correspondence: rybka@tf.czu.cz
Abstract:
This article is aimed at the analysis of the hop drying process that has been carried out
in the chamber dryer of Rakochmel Co. Ltd. in Kolešovice with the Saaz hop variety. The values
measured by means of dataloggers as well as fixed sensors show an identical trend. When the
hops fall over from one slat box onto another, the drying air temperature declines and the relative
humidity rises. A sharp increase in the relative humidity gradually decreases starting with the first
slat box and finishing with the emptying conveyor, which points to a gradual levelling of the
relative humidity and hop moisture. The hop moisture content, determined from laboratory
samples, logically decreases depending on the measurement time. In comparison to belt dryers,
chamber dryers clearly ensure continuous and more gentle drying during which the hops are not
overdried and a moisture content of 10% is achieved practically only at the outlet of the dryer
prior to conditioning.
Key words:
dryer monitoring, hop cones, quality of hops