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.

The classic Coffee Brewing Control Chart (BCC) was originally developed in the 1950s. It relates coffee quality to brew strength and extraction yield, and it is still widely used today by coffee industry professionals around the world to provide guidance on the brewing of coffee. Despite its popularity, recent experimental studies have revealed that sensory attributes and consumer preferences actually follow much more complicated trends than those indicated by the classic BCC. Here, we present a methodology to synthesize the results of these recent studies on drip‐brewed coffee to generate new versions of the BCC: a new Sensory BCC that displays a broad array of statistically significant sensory attributes across typical total dissolved solids and percent extraction ranges, a new Consumer BCC that highlights the existence of two preference clusters with different likes and dislikes across those ranges, a new Sensory and Consumer BCC that combines both sensory descriptive and consumer preferences on the same chart, and a more streamlined BCC that omits consumer preferences and focuses on the overarching sensory descriptive trends. The new BCCs provide more accurate insight on how best to brew coffee to achieve desired sensory profiles. Practical Application: Through the manipulation of yield and extraction parameters, the new Sensory and Consumer Coffee Brewing Control Chart presented here can be used by brewers of drip coffee to design coffees with specific sensory profiles and match the preferences of different consumer types.

The Coffee Cuality Method provides a comprehensive assessment of the sensory quality of coffee that includes an overall quality rating, just-about-right (JAR) scaling of select attributes, check-all-that-apply (CATA) selections from a list of sensory and holistic attributes and open comments. We validated the method with 56 expert coffee tasters by comparing Coffee Cuality with their customary method (i.e., SCA’s, Q-grading or company’s own) for the evaluation of the sensory quality of 12 specialty coffees and commercial blends brewed with their preferred method (cupping, drip, pour over or espresso). A subset of 18 experts then participated in focus groups on the method. Quality mapping (principal component and cluster analyses of the quality ratings) showed consistency among the experts’ overall quality ratings regardless of brewing method, with the dark roasts rated systematically lower than the light- and medium-roasted coffees. Penalty analysis relating JAR ratings to quality scores showed that too dark of a roast or a beverage color and too low of an acidity had the largest (negative) impact on quality. The map of sensory and holistic attributes derived from CATA selections by correspondence analysis, and the word clouds of those selections showed which attributes drove quality ratings, positively or negatively. Focus groups with a subset of the experts suggested improvements to the evaluation protocol and scorecard. By deconstructing, documenting and justifying coffee quality ratings, Coffee Cuality offers a valuable alternative to conventional evaluation protocols.

Volatile phenols (VPs) are present in fresh smoke from wildfires due to thermal degradation of wood lignin and can absorb into grape berry skins where they are rapidly glycosylated. VPs and their glycosides can impact the sensory profile of wines that are characterized by smoky, medicinal aromas and a retro‐nasal ashy “aftertaste.” Anecdotal evidence indicates 15–20% of consumers cannot distinguish the retro‐nasal ashy characteristic of smoke taint. It is difficult to mimic smoke‐tainted wine through spiking with related smoke marker compounds due to their complex synergistic interactions with the wine matrix. This study compared smoke‐impacted and non‐smoke‐impacted wines of Cabernet Sauvignon, Malbec, and Syrah varieties made from the same location (Napa and Sonoma). Smoke‐impacted grapes were intentionally smoked on drying tables or naturally exposed to smoke during wildfires. The wines were blended through serial dilutions, achieving different levels of smoke impact. The free, total, and bound VPs of all wines were determined by GC‐MS and LC‐QTOF‐MS, respectively. Wines were sensorially evaluated by 62 wine experts and 58 regular wine consumers separately; using a series of hedonic, Just‐About‐Right, and Check‐All‐That‐Apply questions. Correspondence analysis determined that different levels of smoke impact were detected differently by wine experts and consumers. Experts could distinguish smoke impact at lower levels, as determined by VP analysis, and compared to consumers who were generally only able to distinguish smoke‐impacted wines at higher levels. Further difference testing with an additional group of wine consumers, saw an increase in the sensitivity towards smoke when consumers were trained to identify/recognize the ashy attribute. Practical Applications: This research provides winemakers with valuable insights into how wildfire smoke impacts wine flavor and the levels at which both expert and non‐expert consumers can detect smoke taint. By understanding these sensory thresholds, wineries can make informed decisions on whether and how to treat smoke‐affected wines—particularly through blending strategies. This enables them to manage quality in smoke‐exposed vintages and transform wines that might otherwise be unsellable into acceptable, marketable products.

The wildfires that swept through Napa Valley in 2020 caused an estimated USD$3.7 billion economic loss to the grape and wine industry. The wines made from smoke-impacted grapes are often described as medicinal, smoky, and possessing a retronasal ashtray character. However, matrix differences among varieties and winemaking styles can impact smoke taint expression as well as the synergistic effects among the volatile phenols responsible for these off-flavors. Serial dilutions of non-impacted and impacted (intentionally smoked post-harvest) wines were used to create wines with differing levels of smoke impact for two wine regions (Napa and Lodi) and styles of Cabernet Sauvignon that were fermented and finished in stainless steel (SS) or subsequently aged in new oak barrels for 12 months. Gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-triple quadrupole mass spectrometry (LC-QqQ-MS) were used to quantify free and total volatile phenols (VPs), and individual bound glycosides, respectively. Descriptive analysis using trained judges and Wine Cuality™ evaluations with wine experts were used to evaluate the sensory characteristics and overall quality of the wines, respectively. Generally, barrel-aged wines saw a decrease in the level of “ashy aftertaste” and smoke-related attributes for both Cabernet Sauvignon wines as compared to their stainless-steel counterparts. Wines with high levels of smoke impact received significantly lower quality ratings ( p < 0.05). Interestingly, wines with low levels of smoke-impact consistently received a slightly higher quality rating though not statistically significant when compared to their non-impacted counterparts. These findings contribute to our understanding of grape smoke exposure at different levels of taint and demonstrate the potential value of barrel aging to mitigate overall smoke perception in wine across these taint levels.