Direct Electrochemical Appraisal of Black Coffee Quality Using Cyclic Voltammetry
Robin E. Bumbaugh and researchers from the Hendon Coffee Lab at the University of Oregon and from Drexel University published this paper in Nature Communications in 2026, with support from the Coffee Science Foundation, underwritten by Nuova Simonelli. Refractometers measure coffee strength but can’t tell what a coffee contains. The authors tested whether cyclic voltammetry, which measures how a liquid responds to a changing electrical voltage, could measure both strength and roast level directly in brewed coffee.
The paper will interest roasters and quality-control professionals looking to understand methods for fast and accurate chemical analysis of brewed espresso.
Read the article in Nature Communications.
Value and Virtual Reality: Leading Research to Better Understand What Drives Consumer Decisions
Laurel Carmichael, SCA Content Development Manager, speaks to researchers at Ohio State University about their ongoing research into the attributes on coffee labels that drive value for consumers. The team built a virtual reality test environment based on a real café, designed to closely emulate a real context in which consumers make decisions. They also tracked how consumers respond to both sensory attributes (what they can taste) and the information on the label.
This article is a work-in-progress report on this research project but already hints at some very exciting findings about consumer decision-making—useful for those in retail coffee marketing and sales.
Access the article free with an SCA Portal account (choose Associate Member).
The Color in Your Cup: Roast Level and Brew Temperature Significantly Affect the Color of Brewed Coffee
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).
Towards a Deeper Understanding of Cold Brew Coffee | Julia Leach, Peter Giuliano, William Ristenpart
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.
The Impact of Brew Temperature and Extraction on the Sensory Quality of Drip Brew Coffee
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.
Cold vs. Iced: Using Sensory Analysis to Test the Claim that Cold Brew is Sweeter and Less Acidic
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).
Dialing In, Decoded: How Electrochemistry Helps Us Understand Espresso Extraction
The SCA’s Content Development Manager, Laurel Carmichael, speaks to researchers at the Hendon Coffee Lab about their chemistry lab that looks like a café and about how they use electrochemistry and design of experiments to better understand the complexities of espresso extraction. Electrochemistry allows the researchers to measure the chemical composition of espresso in real time, and advanced statistical modeling means the beverage chemistry can be correlated with different variables manipulated during extraction.
This article is valuable to trainers, manufacturers, and readers who want to understand the future of espresso extraction beyond the metrics of TDS and extraction percentage.
Access the article free with an SCA Portal account (choose Associate Member).
Chemical Strategies to Mitigate Electrostatic Charging During Coffee Grinding
Joshua Méndez Harper, Robin E. Bumbaugh, and Christopher H. Hendon published an article in iScience in 2024 discussing CSF-supported research into static electricity generated during coffee grinding. They investigated four strategies to mitigate electrostatic charges, assessing their respective impacts on practical outcomes—such as retention of grounds—and on espresso extraction, including evenness and concentration of brewed coffee beverages.
The findings are valuable to anyone wanting to optimize extraction workflow to improve efficiency and manipulate sensory outcomes.
Towards a Deeper Understanding of Espresso Extraction
In this lecture from Re:co Symposium 2023, Professor Christopher H. Hendon of the Hendon Coffee Lab at the University of Oregon outlines the CSF-supported project—underwritten by Nuova Simonelli—on understanding espresso extraction. Hendon covers how his team is measuring espresso chemistry, correlating those measurements to sensory attributes, and laying the groundwork for science-based, usable tools for the coffee industry.
The lecture is interesting for trainers, researchers, manufacturers, and anyone wanting to build a deeper understanding of coffee chemistry.
It’s Electric: Understanding—and Reducing—Static Electricity During Grinding
Dr. Joshua Méndez Harper and Dr. Christopher H. Hendon discuss the chemistry and physics of how static electricity occurs during coffee grinding. They explain how triboelectricity (the type of static electricity generated when two different materials touch) affects espresso extraction and outline strategies to mitigate it.
This plain-language version of their academic article on the same topic is useful to baristas, trainers, competitors, manufacturers, and anyone designing a workflow to extract espresso in ways that optimize sensory characteristics, reduce mess, and reduce unwanted electric shocks!
Access the article free with an SCA Portal account (choose Associate Member).
An Electrochemical Appraisal of Coffee Qualities
Robin E. Bumbaugh, Doran L. Pennington, and colleagues at the University of Oregon and Drexel University, led by Christopher H. Hendon, report CSF-funded research, underwritten by Nuova Simonelli. The research asked whether an electrochemical test, conducted on brewed coffee, can measure a coffee's strength and roast color, something a refractometer alone can’t do.
The researchers found that the test’s signal rises with strength (TDS) and is weaker for darker roasts. In a blind trial with four batches from a UK roaster, it identified the batch the roaster had rejected, even though TDS readings for all four were statistically identical.
The article is useful for roasters and quality-control teams interested in faster, instrument-based ways to check batches beyond refractometer readings.
Grounding Green Grading in Sensory Science: Research to Understand Physical Coffee Defects
The SCA’s Publications Manager, Laurel Carmichael, introduces a Coffee Science Foundation research project on the sensory impact of physical defects in green coffee, undertaken at the Coffee Excellence Center at the Zurich University of Applied Sciences. The plain-language article offers a preliminary overview of the research in progress, explaining the motivations for the research and the study design and hinting at preliminary findings.
The article offers a plain-language foundation for anyone wanting to understand the current defect system, why new research was necessary, and how the research will support the development of new standards for physical coffee assessment. It is especially recommended for trainers, Q graders, and green coffee professionals.
Access the article free with an SCA Portal account (choose Associate Member).
Sweetness in Coffee: Sensory Analysis and Identification of Key Compounds
In this lecture from Re:co Symposium 2023, Dr. Nancy Cordoba of the Flavor Research and Education Center at Ohio State University discusses research into coffee sweetness.
She covers recent CSF-supported research confirming that, counterintuitively, the sweetness in coffee does not come from sugars in the bean, and she explores the mystery this creates: if sugars do not make coffee taste sweet, what could be the reason for the sweet taste of high-quality coffee?
Recommended for researchers, roasters, processors, and anyone wanting to understand recent science on coffee sweetness.
Watch the lecture on the SCA Youtube channel.
How Sweet Coffee Tastes! Towards An Understanding of Coffee Sweetness
Researchers Dr. Nancy Cordoba and Dr. Devin Peterson, joined by Peter Giuliano, share early results of a multiyear Coffee Science Foundation research project, undertaken at the Flavor Research and Education Center at Ohio State University, to establish foundational knowledge about the phenomenon of sweetness in coffee.
The research found that sweetness in coffee is a real phenomenon that tasters can consistently perceive. The article also explores potential hypotheses, including whether sweetness could be caused by sugars, aromatic compounds, or other factors.
This resource is great for trainers, roasters, researchers, and anyone trying to understand one of coffee’s ongoing mysteries: what makes it sweet?
Access the article free with an SCA Portal account (choose Associate Member).
CSF Releases Request for Proposals on Discovering How Value Is Created in Coffee and How It Can Be Maximized
The Coffee Science Foundation (CSF) has released a Request for Proposals, seeking researchers to investigate how value is created in coffee and how it can be maximized. We encourage anyone with a background in proven record of accomplishment in economics, business, economic sociology, consumer science, anthropology or related disciplines to submit!
CSF Releases Request for Proposals for Defects Research
The Coffee Science Foundation (CSF) has released a Request for Proposals, seeking researchers to investigate the impacts of green coffee defects on sensory attributes of coffee. We encourage anyone with a background in coffee defects, agronomy, postharvest processing and sensory science to submit! The complete RFP is available here.
Specialty Coffee Production Costs: The Case of Honduras and El Salvador
Coffee is an important agricultural commodity for many Latin American countries. In El Salvador and Honduras, the countries where we conducted this study, coffee is one of the leading agricultural export crops. Moreover, specialty coffee exports account for a substantial share of these exports. Despite the importance of coffee in these countries, multiple gaps in the literature remain with respect to the cost structure and profitability of specialty coffee production. Of particular interest is the cost of labor, which is expected to be higher. Moreover, little is known about workers’ perceptions of working conditions on specialty coffee farms. Therefore, this study had four objectives: 1) To document production practices, input use, and costs (including labor) in the production of specialty coffees; 2) to model and estimate the complete cost structure of producing specialty coffees; 3) to evaluate the profitability of the production of specialty coffees under different labor costs; and 4) to evaluate workers’ perceptions about labor practices used to produce specialty coffees.
An Assessment of Experimental Evidence in the Coffee Sector
Most coffee farmers are smallholders and about half of them live below the international poverty line of US$3.20 a day. These farmers are highly reliant on coffee as a source of primary income but face unique challenges in improving production and productivity. Several interventions and programs, aimed at enhancing productivity, profitability, and farmers’ income, have been rolled-out in agriculture, in general, and in the coffee sector, in particular. However, very few of these have been rigorously evaluated. This paper aims to provide a comprehensive assessment of the effects of different interventions, primarily from field experiments, and highlight under which conditions and where these have been most successful in improving coffee farmer productivity and income. The paper concludes with policy implications and some potential directions for future research.
What Would it Cost? Calculating Specialty Coffee Farmworker Living Wages in Honduras and El Salvador
Read the full article on SCA News and 25.
Professors CARLOS CARPIO, PhD and LUIS SANDOVAL, PhD worked with BRENDA MAMANI, MSc to ask: what are the living wages in El Salvador and Honduras, and how would current total costs and profitability of coffee production be affected if farmworkers were paid living wages?
Cost and Profitability Analysis of Producing Specialty Coffee in El Salvador and Honduras
Read the full article in the Journal of the American Society for Horticultural Science.
In Honduras and El Salvador, coffee (Coffea arabica) is one of the leading agricultural exports, and the share of specialty coffee is growing each year. However, despite the importance of specialty coffee production and exports, there is a knowledge gap regarding its cost structure and profitability, particularly those associated with labor costs. The specific objectives of the study were to determine the cost structure of specialty coffee in Honduras and El Salvador and to estimate the costs and profitability of producing specialty coffee in these countries. A semi-structured survey instrument was administered to 14 farmers in Honduras and El Salvador selected as a convenience sample to represent different farm sizes, regions, and specialty-conventional and organic production systems. Specialty-conventional refers to high-quality coffee with or without certifications. Then,cost-profitability models were developed using an economic cost approach, which considered cash, noncash cost, and the opportunity costs of inputs. The results showed that although both countries are neighbors and economically and culturally similar, the cost structure of producing specialty coffee differed significantly. Costs were lower and profits were higher in Honduras than in El Salvador, and the specialty-conventional coffee production system was more profitable than the organic production system.