Sara E. Yeager of the UC Davis Coffee Center summarizes a paper she coauthored, “Roast Level and Brew Temperature Significantly Affect the Color of Brewed Coffee,” published in the Journal of Food Science in 2022. 

The study grew out of research, supported by the CSF and underwritten by Toddy, that compared hot and cold brew, and it looked at how origin, roast level, and brew temperature relate to the color of brewed coffee. Color matters because research shows that consumers value coffee color when making purchasing decisions.  

The article will interest roasters, café owners, and ready-to-drink producers who want to understand how their brewing choices change the appearance of their brewed coffee products. 

Access the article free with an SCA Portal account (choose Associate Member). 

In this panel from Re:co Symposium, Julia Leach of Toddy, Peter Giuliano of the CSF, and William Ristenpart of the UC Davis Coffee Center present findings from a multiyear project on cold-brewed coffee. 

They explore and scientifically debunk common misconceptions about cold brew and highlight attributes associated with cold-brewed coffee. The panel discussion covers multiple published research papers within the broader project, including those on beverage color, measured and perceived acidity, and other sensory attributes. 

This discussion is great for trainers, brewers, consultants, and product developers wanting an overview of the market appeal and sensory potential of cold brew coffee. 

Watch the discussion on the SCA Youtube channel.

Mackenzie Batali, a graduate student researcher at the UC Davis Coffee Center, shares an overview of CSF-supported research on brewed coffee. The lecture explores how temperature, at a fixed total dissolved solids and percent extraction, affects the quality of drip-brewed coffee as assessed by an expert panel. In addition, the lecture discusses work to expand the classic Coffee Brewing Control Chart with more detailed sensory language. 

This lecture is valuable to baristas, trainers, café owners, and anyone wanting to understand how manipulating brew parameters—especially temperature and extraction—affects the cup. 

Watch the discussion on the SCA Youtube channel.

Lead author Dr. Mackenzie Batali of the UC Davis Coffee Center shares CSF-supported research exploring how the cold-brewing process affects the sensory profile of coffee. The research measured the perception of sensory descriptors such as “floral,” “rubber,” “bitter,” and “sour” in both cold brew and chilled hot brew. The research team also measured the impact of different cold-brewing parameters, such as brewing time. 

This article is useful to anyone making decisions about how to prepare cold coffee beverages, from small-scale home consumption to commercial retail. 

Access the article free with an SCA Portal account (choose Associate Member). 

Coffee Science Foundation Executive Director Peter Giuliano sat down with Dr. Mackenzie Batali, lead author of a recent milestone study, “Sensory Analysis of Full Immersion Coffee: Cold Brew Is More Floral, and Less Bitter, Sour, and Rubbery Than Hot Brew.” They discuss questions such as these: How does cold-brewed coffee differ from hot-brewed coffee? Are the differences chemical, sensory, or both? And how can our industry develop guidelines and best practices for excellent cold-brewed coffee? 

This article is useful for anyone wanting to brew or market cold coffee, on both a small and a large scale. 

Access the article free with an SCA Portal account (choose Associate Member). 

Researchers from the UC Davis Coffee Center share findings from research into the characteristics of cold brew compared with chilled hot brew in the journal Foods. They investigated the common claim that cold brew is sweeter or less acidic than hot brew coffee and performed a systematic study of how extraction temperature affects the sensory qualities of full-immersion coffee. They also considered interactions with other attributes such as coffee origin and roast. 

This article is useful for anyone wanting to make scientifically grounded decisions about how they prepare cold coffee, with a focus on how brew temperature can be used to modulate flavor profile. 
Read the full academic paper in Foods.

Sara E. Yeager and a research team from UC Davis published an article on how roast level and brew temperature affect the color of brewed coffee in the Journal of Food Science in 2022. This research was supported by the CSF with underwriting from Toddy. The researchers tested coffees from three different origins, roasted to three different levels and brewed at three different temperatures, to determine how much impact each variable had on beverage color. 

Their research is particularly relevant to those retailing coffee in transparent vessels or wanting to manipulate beverage color to match consumer preferences. 

Read the full academic paper in the Journal of Food Science.

Sara E. Yeager, Mackenzie E. Batali, Jean-Xavier Guinard, and William D. Ristenpart of the UC Davis Coffee Center published a paper in Critical Reviews in Food Science and Nutrition in 2021. They gathered and analyzed the available literature on coffee acid composition, with a focus on the organic and chlorogenic acids that contribute to sensory properties. 

Their review covered studies on both Coffea arabica and Coffea canephora, drawing from 129 publications and over 8,000 discrete data points. Their findings indicate interesting interactions between roast level, acid concentration, and sensory profile. 

This article is useful to roasters, quality-control professionals, and anyone trying to understand how roasting can affect measurable acids and sensory properties. 

Read the full academic paper in Critical Reviews in Food Science and Nutrition.