Effects of capsule parameters on coffee extraction in single-serve brewer.

In this study, the effects of particle size (222 to 1085μm), packing amount (7.1 to 10.7g), and brewing volume (113 to 226mL) on physiochemical properties of coffee brews, prepared using a commercial single-serve brewer, were investigated. The results show that decreasing particle size increased the extraction yield by about 63% without changing the extraction of acidic and phenolic compounds, implying finer grinds potentially could be used to reduce the use of coffee ground. Increasing packing amount had no effect on the extraction yield, but did increase the concentration ratio of acidic to phenolic compounds, thus changing the flavor profile of the brew. >80% of the soluble solids were extracted within the first 113mL, while further brewing diluted the brew and introduced more bitter and astringent compounds. This study increased the understanding of single-serve brewing process, which is important to optimize brew quality and minimize production cost.