Study on coffee flavour of various pour-over brews

Abstract

Coffee filters and drippers advertised with various functions such as balanced flavour, sweeter taste and plentiful coffee scene are popular options for hand-brewed coffee lovers. This study investigated the flavour of filtered coffee brewed by various coffee filters including Hario V60 filter, Kalita filter, flannel cloth filter and stainless-steel (screen) filter based on the physical and chemical properties of the beverages. The results showed that the extraction time of V60 and flannel cloth filter were shorter. Kalita filter offered longer extraction time and obtained the highest amount of chlorogenic acids than other drippers. In the volatile profiles of aroma compounds, flannel cloth and stainless-steel filters obtained higher total volatile compounds that may due to less volatiles were absorbed by filter material compared with paper filters, V60 and Kalita. Combined physical and chemical data among four extraction methods, partial least squares-discriminant analysis (PLS-DA) was able to separate samples into approximate four clusters. 2-Acetylfuran and 3-methyl-phenol were found fluctuated wildly among samples and would be important factors for the differentiation of pour-over coffee. This study suggested that the four coffees brewed by different filters have their own characteristic aroma profiles and did show their differences based on the chemical compositions caused by dripping speed and the interactions with filters.