Sensory Analysis of Full Immersion Coffee: Cold Brew Is More Floral, and Less Bitter, Sour, and Rubbery Than Hot Brew

Abstract

Cold brew coffee is often described as sweeter or less acidic than hot brew coffee. Such comparisons, however, are potentially confounded by two key effects: different brew temperatures necessarily change the extraction dynamics and potentially alter the resulting brew strength, and different consumption temperatures are well known to affect perceived flavor and taste. Here, we performed a systematic study of how extraction temperature affects the sensory qualities of full immersion coffee. The investigation used a 3 × 3 × 3 factorial design, with coffee from three different origins representing different post-harvest methods (washed, honey-processed, and wet-hulled), each roasted to three different levels (light, medium, and dark), and each brewed at three different temperatures (4 °C, 22 °C, and 92 °C). All coffees were brewed to equilibrium, then diluted to precisely 2% total dissolved solids (TDS) and served at the same cold temperature (4 °C). We find that four attributes exhibited statistically significant variations with brew temperature for all origins and roast levels tested, with bitter taste, sour taste, and rubber flavor all higher in hot brewed coffees, and floral flavor higher in cold brewed coffee. However, there were strong interactions with origin and roast, with several additional attributes significantly impacted by temperature for specific origins and roast levels. These results provide insight on how brew temperature can be used to modulate the flavor profile of full immersion coffee.

Proof of Concept for Cell Culture-Based Coffee

“…Finally, it should be noted that the method of coffee preparation has been shown to strongly influence the sensory attributes of the resulting brew such as roasted odor, other aroma attributes, sourness, and bitterness. ,,, In this study, the cell coffees were compared to diluted dark roast coffee and all samples were brewed as filtered coffee. Future work should also account for the differences in the roasted biomass such as particle size and adapt the brewing process accordingly.…”

The Potential of Spent Coffee Grounds in Functional Food Development

“…The highest scores in sensory evaluation of cold-brew coffee, characterised by strong sweetness, fruity and floral flavours, medium bitterness and acidity, and a creamy body, were found after a 14 h extraction of coarse ground medium-roasted coffee at room temperature of 20 °C [ 38 ]. Cold-brew coffee showed increased floral flavour when compared to hot-brew coffee, and hot-brew coffee exhibited increased bitterness, sour taste and rubber flavour [ 39 ]. The differing results from different extraction procedures means that it is not possible to extrapolate the daily doses of caffeine and CGA from the number of cups of coffee consumed per day [ 37 ].…”

Coffee brewing sonoreactor for reducing the time of cold brew from several hours to minutes while maintaining sensory attributes

“…Coffee enthusiasts continually seek premium coffee beverages, driven by a desire for brews with distinct sensory qualities. Cold brew coffee, with its reduced acidity, enhanced sweetness, and floral aroma [5] , [6] , has recently surged in popularity. It is estimated that the cold brew market will continue to grow, capturing a significant portion of the coffee market.…”