
Photo by Dan Shryock
Centering Research on Coffee
Professor William Ristenpart inside the “The Design of Coffee” lab.
DAVIS, CALIFORNIA
By Dan Shryock
The room looks like any other college lab with a significant exception. Drip coffee makers, grinders, AeroPresses, and Chemex urns replace typical laboratory apparatus. Coffee beans are the focus of attention.
This is the setting for “The Design of Coffee: An Introduction to Chemical Engineering,” an undergraduate course at the University of California, Davis. Approximately 2,000 students enroll in this class each year. It is one of the most popular electives on this Northern California campus and it also holds a lofty credit as the birthplace of the UC Davis Coffee Center.
William Ristenpart and Tonya Kuhl, co-directors of the coffee center and professors at UC Davis, developed the course in 2012 to enhance their understanding of laboratory techniques. “We were sitting around thinking about how we could improve our labs and do things that are interesting,” Ristenpart recalls. “Then we asked ourselves ‘Why don’t we have a course using coffee as a tool to teach core engineering and scientific principles.’
“Coffee has its mystique,” he says. “People don’t know much about it except that they drink it a lot.”
The class’s success led Kuhl and Ristenpart, who both have doctorates in chemical engineering, to look beyond an introductory course. “It quickly became apparent there was a huge unmet need not only in terms of education but in terms of research,” says Ristenpart. “We started putting together a coffee initiative on campus.”
The Coffee Center, housed in the UC Davis College of Engineering, is the first multidisciplinary university research center in the US to address the challenges and needs of the coffee industry, according to the university.
As interest in the center grew within the coffee industry, a building – a potential home – became available on campus. Soon after, the university gave permission for organizers to begin fundraising for a permanent coffee research center. Donations already total $2 million and both research projects and building renovations are moving ahead.
“One of the goals of the coffee center is to serve as a bridge between coffee producing regions,” Ristenpart says over a cup of arabica. With research, he adds, people can learn how to grow, process, roast, and brew coffee to obtain a specific taste no matter where the coffee cherry originates.
The industry has taken notice. La Marzocco donated $750,000 in January 2018 to help pay for building renovations and support research. Others followed.
“The forward motion of the coffee industry has always been the core of our mission at La Marzocco,” chairman of the board Kent Bakke said at the time of the donation. “We believe the Coffee Center at UC Davis represents a renewed focus on understanding the science behind coffee that will lead us to better practices for growers, importers, roasters and cafes. Our international team is expanding our research and educational initiatives and we hope UC Davis can be a partner in this effort.”
Donors include:
- A group of Nicaraguan ventures and supporters including Edwin Rizo, Rizo-Lopez Foods, Bencafe S.A. Nicaragua, Mercon Coffee Corp, Café Soluble S.A., and Cisa Agro S.A. ($500,000)
- Wilber Curtis Company ($250,000)
- Peet’s Coffee & Tea ($250,000)
- Josuma Coffee Company ($150,000)
- Behmor ($100,000)

Centering Research on Coffee
Research projects are underway. Ristenpart and professor Jean-Xavier Guinard are teaming with the Specialty Coffee Association on a two-year project to rethink everything from scientific assumptions, sensory data, and measurement tools, to the consumer research behind the industry’s understanding of coffee. Guinard, a sensory scientist, is known for creating a new coffee tasters flavor wheel.
“SCA developed a part of (the flavor wheel) in collaboration with the sensory science department at UC Davis and we currently are supporting two major research projects on brewed coffee at the center,” says Peter Giuliano, the association’s chief research officer. “Additionally, we work with the coffee center lab to do testing for our certified home brewer program.”
Giuliano underscores the university’s international reputation as a leader in agriculture and food-focused research and its history in the fields of wine, beer and sensory science. “The coffee center is a continuation of that tradition and we know that through science, research and education, UC Davis can contribute to coffee in the same way it did those other special agricultural products,” he said.
As evidence of the university’s research success, professor Juan Medrano, a geneticist in the UC Davis College of Agricultural and Environmental Sciences, co-authored the first public genome sequence for Coffea arabica. That genetic road map was made available in January 2018.
Collaborating with Medrano on the sequencing were plant scientists are Allen Van Deynze and Dario Cantu, and post-doctoral research scholar Amanda Hulse-Kemp, all from UC Davis. And while their work is not affiliated with the coffee center, both Deynze and Cantu are among the more than 35 members of the center’s faculty.
Ristenpart envisions several long-term initiatives. A planned network of international field stations, for example, would channel on-the-ground research data for comparative analysis. One station is under development in Nicaragua.
Another is an extended study of the effects of climate during the storage of green beans. “There has not been a lot of research on that,” he says. “We’ll have a whole dedicated room with banks of environmental chambers each of which can successfully modulate the temperature and humidity profile. We can take the same beans, store them under different conditions and see how the effects of chemical and biological degradation mechanisms affect coffee quality through storage.”
Ristenpart also sees growth in coffee education. “Something sorely lacking in the coffee industry is a pipeline of talent. If you have a vineyard and you want someone with expertise in how to run a winery, you know where to go,” he says, referring to the university’s viticulture and enology programs. “Right now, coffee doesn’t have that. What I see long term – 10 years is probably the right time scale – is a master’s degree focusing on coffee science. All the training focusing on coffee. That would go a long way toward making a very rigorously trained, scientifically adept workforce for the coffee industry.”