UC Davis Coffee Center Developing Best Ways To Farm, Roast, Brew Coffee – CoffeeTalk

Coffee, the most consumed beverage in America and third-most globally, is poorly understood. UC Davis researchers are working with the $28 billion American coffee industry to tackle challenges such as sustainable farming, grading bean color, and measuring consumer taste preferences. The UC Davis Coffee Center, opened in May, is the only university coffee lab in the country and aims to become the global leader in coffee studies, science, research, and education.

Researcher Irwin Ronaldo Donis-González, assistant professor in biological and agricultural engineering, said that there is very little knowledge about coffee, even though it is one of the most exchanged commodities in the world. The goal for the Coffee Center is for UC Davis to become the global leader in coffee studies, science, research, and education.

The Coffee Center’s body of coffee research is not new, but its group of coffee researchers has been called “the Coffee Center” colloquially for years. Timothy Styczynski, a professional micro-roaster who owned and operated Bridge Coffee Co., was drawn to the Coffee Center because of his decades-long passion for coffee and the potential for new research.

Styczynski is now the Coffee Center’s head roaster, managing the center part-time, participating in its research studies, and roasting bags of coffee to sell in the campus bookstore. He is also a certified Q grader, one of fewer than 600 in the United States, which is internationally recognized in the coffee industry and is akin to a sommelier for wine.

The Coffee Center’s goal is to fill the knowledge gap and serve as a hub for all coffee-related topics across campus. The center aims to provide a platform for students to learn about coffee, develop their skills, and contribute to the advancement of the coffee industry.

UC Davis’ Coffee Center was established in 2013 by engineering professors Greg Ristenpart and Tonya Kuhl to spark interest in chemical engineering. The first university-level course about coffee in the nation, “The Design of Coffee,” was created in 2013, with only 18 students enrolled at the time. This academic year, 2,091 students signed up for the course.

UC Davis has a laboratory dedicated to coffee, where students learn engineering concepts in lectures that they apply in the coffee lab. In their final week, students must brew the best-tasting coffee using the least amount of energy. Students enter the course with various levels of coffee knowledge and experience, learning everything from reverse engineering a drip coffee brewer to understanding coffee as a colloidal fluid.

Colloids are so small they can’t be seen with the naked eye, but the quantity and nature of the colloids can affect the mouthfeel and flavor of coffee. For example, pouring boiled water straight over coffee grounds results in a thick, gritty drink, which is the technique used to make Turkish coffee. After drinking a cup of Turkish coffee, there are enough spent grounds left at the bottom to perform tasseography — fortune-telling using coffee grounds.

Understanding the many chemical engineering concepts in the coffee-making process is important for coffee companies that want to make a superb product. For Sage Ikeda, a second-year mathematical analytics and operations research major, taking “The Design of Coffee” helped him realize the many career opportunities available in the coffee industry. He now works part-time at the Coffee Center.

Today, “The Design of Coffee” is well-known among UC Davis students and has been included in many class bucket lists for years. The rapidly growing popularity of the course combined with interest from the coffee industry led to the creation of the new Coffee Center.

Coffee farming is a significant aspect of global coffee production, with coffee cherries being the main crop. However, coffee plants face challenges in the United States due to temperature drops and language barriers. Most coffee is grown in tropical regions on mountain sides, far from most Americans. This has led to a lack of awareness and appreciation for coffee, with many American coffee importers having never visited a coffee farm.

Coffee Center researchers like Donis-González are working to close this gap by researching coffee farming in Guatemala and focusing on post-harvest handling, tracking produce from field to consumer, and reducing energy consumption during processing. Laudia Anokye-Bempah, a Ph.D. candidate in biological systems engineering, is conducting studies to determine how coffee roasting methods influence taste.

Styczynski encourages coffee consumers and researchers to keep coffee farmers in mind, as the 25 million families that grow coffee worldwide have few other means for sustainability in their communities. By taking care of the plants, the better we take care of the communities that grow and sell them.

Food waste is another issue that coffee center researchers are addressing. After collecting coffee beans from cherries, the remaining skin and pulp, called cascara, is often discarded. The process of growing, pruning, fertilization, and spraying takes three years, and then the cherries are picked by hand. Some cascara is dried and turned into tea, but Ristenpart compares this process to trying to create wine out of raisins, which results in a drink that tastes like oxidized, dry fruit.

In conclusion, coffee farming and consumption are interconnected, with coffee farmers and consumers playing crucial roles in maintaining the sustainability of coffee production.

Melina Devoney and Timothy Buensalido, UC Davis alums in international agricultural development, conducted research on cascara, a type of coffee bean, to be upcycled and turned into jelly. Their goal is to reduce waste and provide farmers with more revenue. Coffee farmers face constant economic stress and uncertainty, with most earning only a few dollars per day.

The researchers conducted sensory surveys at the Coffee Center, which resulted in high liking scores for cascara, suggesting that it could be made into a marketable jelly product that would likely sell well. Bill Ristenpart, who worked with Devoney on the research project, has become passionate about the topic, trying cascara on a variety of food products. He said he hopes to someday build a greenhouse behind the Coffee Center, where students can grow their own coffee plants, like how UC Davis’ Robert Mondavi Institute for Wine and Food Science has a vineyard in its backyard.

Green coffee beans have not been roasted and have a light, herbal smell. The Coffee Center’s Green Bean Storage Laboratory, funded by Nicaraguan Coffee Growers, is lit with natural light and spacious, with concrete floors, white walls, an industrial ceiling, and a variety of bags and boxes brimming with green coffee beans on warehouse shelves. Green coffee beans have not been roasted and smell light and fruity, almost like hay. They are smooth and pistachio-colored but feel nothing like pistachios.

Researchers at the Coffee Center use the environmental chambers to test similar scenarios using small batches of coffee beans. The degraded coffee is tested by a sensory team, determining exactly how much degradation over time affects flavor. The goal in testing bean degradation is to see which strains are highest quality, which could save coffee growers and shippers significant money and time.

Ph.D. candidate Laudia Anokye-Bempah works in her lab at the UC Davis Coffee Center in 2022 before it was renovated. She pulls out a roaster’s sample tryer to examine the roasting coffee beans using sight and smell.

Adjacent to the storage lab is the Peet’s Coffee Pilot Roastery, which has two large roasters, one Aggie Blue and the other Aggie Gold. Timothy Styczynski feeds green coffee beans into the blue roaster, manipulating how sweet the coffee is, how sour it is, how roasty it tastes, if it’s thinner or heavier in body and mouthfeel from the same beans using different recipes.

Head roaster Timothy Styczynski checks the roast using sound and smell. Roasting coffee beans sounds like popping popcorn and, surprisingly, does not smell anything like brewing coffee. The smell is more warm, light, and soft than the smell of a coffee shop.

In conclusion, the research aims to reduce waste and provide farmers with more revenue by turning cascara into a marketable jelly product. By understanding the process of roasting and checking coffee beans, researchers hope to help farmers and consumers make informed decisions about their coffee choices.

Anokye-Bempah and Styczynski conducted a research paper on the impact of coffee roast profile, which is the temperature versus time inside the roaster, on the perceived sourness of the resulting coffee. They produced various roasts, pulling samples per minute and dropping them into liquid nitrogen to freeze the chemical process in time. They found that the peak always happened statistically at the same time regardless of coffee origin, coffee bean, and coffee roast.

The results provide insight on how to manipulate and achieve desired sourness during roasting, allowing roasters to tailor their roasts to create a cup of coffee with the perfect balance of acidity. The coffee industry has had a hard time categorizing the thousands of colors in coffee beans, as they come in thousands of different flavors and colors. Professor Bill Ristenpart, who is working with the Specialty Coffee Association on creating a universal coffee color grading scale based on Anokye-Bempah’s findings, hopes to create a science-based tool to categorize roasts soon.

A new technology called Roastpic has been developed to improve coffee quality control. The app uses artificial intelligence to grade coffee beans by taking photos of them on a smartphone. The app can determine coffee bean size, color, and defects in a snap, significantly decreasing the time and cost it takes for coffee graders to filter out low-quality coffee beans. Roastpic has three versions: a basic version for hobbyists, a premium version for advanced graders, and a newly released professional version for coffee industry professionals.

Roastpic has grown to a team of 10, composed entirely of faculty and students from the Coffee Center. Keegan Thompson, a fourth-year communication major, has become fully immersed in coffee science after working at Roastpic for a few months. He now holds the title of customer service expert at Roastpic and has become fully immersed in coffee science.

In summary, Anokye-Bempah’s research paper on the impact of coffee roast profile, color grading, and Roastpic has the potential to revolutionize the coffee industry. By utilizing artificial intelligence and a new technology, roasters can now create a more accurate and efficient coffee experience.

In this text, the author discusses a class in coffee tasting and consumer preferences at the University of California, Davis. The class is led by Bill Ristenpart, professor of engineering and co-director of the Coffee Center, who instructs students on how to develop coffee as a sensory experience. The class is an experimental one-unit course focused on coffee as a sensory experience, with students working directly with co-teachers Ristenpart and Styczynski to set up lab equipment and make espresso.

The class begins with 10 students pouring themselves a cup of coffee specially brewed by Styczynski to taste before taking their seats. Styczynski describes the type of beans and brewing process used and asks the class for their thoughts on the coffee’s flavor before a teaching assistant flips through the slides of a presentation titled, “Holiday Blends.” Over the past several weeks, the students have been tasting different holiday blends and learning how to make their own.

The final choice of what holiday blend to sell must be based on consumer hedonic preference testing, a quantitative method in sensory science that measures how much consumers like a product. After finishing their cups of coffee, the students head into the Sensory and Cupping Laboratory, a sleek café-styled room with a service window connecting to the La Marzocco Brewing and Espresso Laboratory. Styczynski and the teaching assistants brew mugs of coffee and slide them through the window to be freshly served to those in the sensory lab.

Five students file into the small sensory room and take seats in individual booths. The room would be pitch dark without red lights shining overhead, which helps mask color differences in the coffees. This allows the students to focus only on the coffee’s flavor, smell, and texture. Thompson opens a small service door in front of each booth to slide in a single mug of hot coffee on a plastic tray. When all the doors are shut, the students take their time sipping coffee while scrolling on their phones to check boxes beside different flavor descriptors.

The students conduct CATA (check all that apply) testing in the Coffee Center’s sensory lab to identify the most prominent flavors in a cup of coffee. The form contains a long list of flavors with checkboxes beside each one. The students select as many flavors as they can taste from options like citrus, caramel, floral, vegetal, nutmeg, and cardboard.

Towards the end of the session, the students head back into the classroom to see their tasting results. On the projection screen, a bar chart reveals the blend’s most-perceived flavors: caramel, nutmeg, and baking spices. Only two students chose potato, and none chose cardboard.

The class agrees that this blend was one of the best so far. The last one, Blend 715, did not do as well, with rough hedonic scores and word clouds emphasizing the flavors “bitter,” “very bitter” and “bread” in enormous font, decidedly not the ideal coffee to sell at the bookstore.

The Coffee Center at UC Davis is transforming the coffee industry by offering a course called “Coffee Tasting Practicum,” which is not only free but also accessible for those who may feel nervous about chemical engineering classes. The course has helped students gain a deeper understanding of the physical and chemical processes of coffee, making it more accessible and enjoyable. The center plans to develop a course that will include the “Coffee Tasting Practicum” as one module in a larger, more formal class that will go deeper into the physical and chemical processes of coffee. The multidisciplinary nature of coffee has attracted over 50 faculty members from various backgrounds and research interests, including agricultural sustainability and the effects of coffee consumption on human health. Despite its popularity and economic profitability, academic funding for coffee research is not reflecting the numbers. Industry professionals are providing philanthropic support to fill this gap. The Coffee Center aims to create a new pipeline of talent and elevate the coffee industry to something more akin to the beer or wine industry.

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