PROBAT developed an apparatus with which the degassing quantity and the temporal degassing behavior of ground coffee can be determined. At the same time, the influence of protective gases which are used for the ground coffee transport and storage like CO2 and N2 on the degassing behavior can be examined. The pressure build-up during the storage in the bin is the factor for the released gas quantity.
It has been examined which effects the roasting time, grinding degree and the surrounding atmosphere in the degassing apparatus have on the degassing behavior. When using protective gases for aroma preservation, it gets obvious that nitrogen as protective gas provides in comparison to carbon dioxide rather for an accelerated degassing of the coffee. This influence is due to the different gas densities of nitrogen and carbon dioxide and thus to the partial pressure influence. Essential influencing factors for the degassing duration are partial drop of pressure and grinding degree: the finer the grain size adjustment, the quicker the degassing.
As variable roasting profiles for the same coffee sort can lead to different degassing curves it is necessary to examine the particular process and the actual coffee sort to receive more precise data. The influences through process and sort can be determined and represented easily with this developed degassing apparatus. Lecture to the topic
