Physical characteristics of picked hops during storage

L Vent, A Rybka
2013 Agronomy Research   unpublished
To prevent interrupting the process of drying or picking due to lack or surplus of hops coming out of the picking line, hops, in most cases are placed in a storage container.. In a container, however, hops are layered, thus temperature and humidity increase owing to an increased intensity of hop cones breathing and an insufficient airing, i.e. they mowburn. In the process of breathing a cone loses important substances which results in its deteriorated quality and correspondingly in the poor
more » ... gly in the poor quality of the final product. Our task was to observe the course of hop temperature and humidity in a storage container and to compare it with the check variant, which was loosely spread hops outside the container. Data of temperature and humidity were continually recorded by COMET D 3631 measuring equipment with N1ATG8/C measuring probe by the Comet System company. Other analogue sensors to measure humidity and temperature were independently installed for checking. The monitoring was each time carried out for 24 hours. During storage both the temperature and humidity of the hops in the container increased substantially, with temperature values reaching up to 49 °C and humidity values 100%. The progress of temperatures was almost identical with all the measurements, that is why we present only the average values. The highest temperature inside the container was in the range of 39 °C to 49 °C with individual measurements. The temperatures of the check samples were identical with the air temperature in the daytime with all the repeats. The maximum temperature of the check samples ranged from 21 °C to 27 °C with each measurement. In the same way as with the temperature, during the individual measurements the humidity showed similar progress and the measurements did not differ from each other in any substantial way. The humidity level in the container rose up to the maximum value of 100% already two hours after the measurement had started and stayed like this until the end. The humidity of the hop check samples was 2.24% higher than the air humidity, which might be explained by water vapour emission due to an increased intensity of hop cones breathing. The conclusion we may draw here says that with an increasing volume and, probably above all, height of the stored hops layer, the influence of the surroundings on the conditions inside the container will decline.