Impact of the human factor on the reproducibility of different coffee brewing methods

Abstract

Filter coffee can be prepared using various methods, most of which are time-consuming and dependent on the skill of the operator/barista. In this regard, a medium-roasted specialty coffee has been selected to test four different filter extraction methods (Pure Brew, V60, AeroPress and French Press). Each method was performed by six different expert baristas to understand the influence of the human factor on the preparation. Pure Brew and V60 reported excellent reproducibility concerning the total dissolved solids, brewing time and amounts of bioactive compounds by HPLC–MS/MS and volatile compounds by GC–MS; while for viscosities analysis, Pure Brew and French Press were detected as the more reproducible. The pressure and turbulence applied by baristas for pouring water during preparation proved to be key variables from the point of view of reproducibility in filter coffee extraction.