Effect of Basket Geometry on the Sensory Quality and Consumer Acceptance of Drip Brewed Coffee

In this work, discrimination tests, descriptive analysis, consumer tests, and total dissolved solids (TDS) were used to evaluate the effects of brew basket geometry on the sensory quality and consumer acceptance of drip brewed coffee. Two basic geometries, semi-conical and flat-bottom, were evaluated in conjunction with coffee roast and particle size. Initial discrimination tests showed that small differences in median particle size were not discernable, but that coffees brewed using either semi-conical or flat-bottom filter baskets were significantly different (P < 0.05, N = 45). Additionally, coffee brewed in the semi-conical basket had significantly higher %TDS, and we estimated a sensory difference threshold of 0.24 %TDS. A subsequent descriptive analysis (DA) showed significant differences by roast for 11 attributes and by grind for six attributes. Although brewing geometry, as a single factor, was only significantly different for three independent attributes (smoke aroma, sweetness, and tobacco flavor), roast × geometry interactions were significant for six attributes (berry flavor, bitterness, burnt wood/ash, citrus flavor, earthy flavor, and sourness) and the grind × geometry interaction was significant for two attributes (bitterness and floral aroma). Attributes showing significant interactions with brewing geometry were also key drivers of consumer liking/disliking. Overall consumer liking (9-point hedonic scale) was analyzed by cluster analysis (N = 85), which revealed four distinct preference clusters. For each cluster, a particular basket geometry and/or roast level showed lesser acceptance. Overall, the results strongly corroborate the hypothesis that basket geometry affects the sensory quality of drip brewed coffee. PRACTICAL APPLICATION: Most Americans consume drip brewed coffee. Improving our understanding of the effects of basket geometry, roast level, and grind size on the total dissolved solids, sensory properties, and acceptability of drip brewed coffee gives producers and consumers alike an opportunity to optimize the sensory quality of their coffee.