Elaine Jutamulia ’24 took a sip of coffee with a few drops of anise extract. It was his second try.
“What do you think?” asked Omar Orozco, standing at a lab table in MIT’s Breakerspace, surrounded by filters, coffee makers, and other coffee paraphernalia.
“I think when I first tried it, it was still quite bitter,” Jutamulia says thoughtfully. “But I think now that it’s steeped a little bit, it’s taken away some of the bitterness.”
Jutamulia and Orozco, currently a senior at MIT, were part of Class 3,000 (Coffee Matters: Using the Breakerspace to Make the Perfect Cup), a new MIT course that began in spring 2024. The course combines courses on chemistry and the science of coffee with practical lessons. experiments and group projects. Their project explored how additives such as anise, salt and chili oil influence coffee extraction – the process of dissolving flavor compounds from ground coffee in water – to improve taste and correct defects. Common brewing mistakes.
Along with tasting, they used an infrared spectrometer to identify chemical compounds in their coffee samples that contribute to flavor. Does anise make bitter coffee sweeter? Could chili oil balance the taste?
“Generally speaking, if we could make a recommendation, that’s what we’re trying to find,” Orozco said.
A three-unit “discovery class” designed to help first-year students explore 3,000 majors was highly successful and welcomed more than 50 students. Its success rests on the drink at its core and the hands-on approach to the class, which pushes students to ask and answer questions they might not have asked otherwise.
For aeronautics and astronautics students Gabi McDonald and McKenzie Dinesen, coffee was the main draw, but the class encouraged them to experiment and think in new ways. “It’s easy to invite people like us, who love coffee, and, ‘Oh my God, there’s this class where we can go make coffee half the time and try all kinds of things?'” McDonald said.
Knowledge that seeps in
The course combines weekly lessons on topics such as coffee chemistry, the anatomy and composition of a coffee bean, the effects of roasting and the brewing process with tasting sessions: students taste coffee coffee brewed from different beans, roasts and grinds. In the MIT Breaker Spacea new space on campus designed and managed by the Department of Materials Science and Engineering (DMSE), students use equipment such as a digital optical microscope to examine ground coffee particles and a scanning electron microscope, which shines electron beams onto samples to reveal cross sections of beans in stunning detail.
Once students learn to use instruments for guided tasks, they form groups and design their own projects.
“The driving force behind these projects is a question they ask about coffee during one of the lectures or a tasting session, or simply something they always wanted to know,” explains Professor Jeffrey Grossman of DMSE, which designed and teaches the course. “Then they will use one or more of these pieces of equipment to shed light on this.”
Grossman traces the origins of the class to his initial vision for the Breakerspace, a materials analysis lab and lounge for MIT undergraduates. Opening in November 2023, the space provides students with hands-on experience in materials science and engineering, an interdisciplinary field combining chemistry, physics and engineering to probe the composition and structure of materials.
“The world is made of things, and these are the tools needed to understand those things and bring them to life,” Grossman says. So he imagined a course that would give students an “exploratory and inspirational boost.”
“The question then was not one of pedagogy, but of knowing: “What is the problem? » In materials science, there are many directions you can take, but if you have one that inspires people because they may already know it and like it, then that’s exciting.
Ambition Cup
That hook, of course, was coffee, the second most consumed beverage after water. This captured the students’ imagination and motivated them to push the boundaries.
Orozco brought a lot of coffee knowledge to the class. In 2023, he taught in Mexico as part of the MISTI Global Teaching Labs program, where he visited several coffee plantations and gained a deeper understanding of the beverage. He learned, for example, that black coffee, contrary to general American opinion, is not naturally bitter; bitterness comes from certain compounds that develop during the roasting process.
“If you prepare it correctly with the right beans, it tastes really good,” says Orozco, a humanities and engineering major. A year later, in 3.000, he expanded his understanding of making good coffee, including through the group project with Jutamulia and other students to fix bad coffee.
The group prepared a control sample of “perfectly brewed” coffee – based on taste, coffee-to-water ratio and other standards covered in class – as well as under-extracted and over-extracted coffee. Under-extracted coffee, made with water that is not hot enough or brewed for too short a time, tastes sharp or sour. Over-extracted coffee, brewed with too much coffee or for too long, tastes bitter.
These coffee samples were given additives and analyzed using Fourier transform infrared spectroscopy (FTIR), measuring how well the coffee absorbed infrared light to identify flavor-related compounds. Jutamulia looked at FTIR readings taken from a sample containing lime juice to see how citric acid influenced its chemical profile.
“Can we find a correlation between what we saw and existing known measurements of citric acid? asks Jutamulia, who studied computation and cognition at MIT and graduated last May.
Another group looked at coffee storage, wondering why conventional wisdom advises against freezing.
“We were just wondering why that was the case,” says Noah Wiley, an electrical engineering and computer science student who is passionate about coffee and owns his own espresso machine.
The team compared methods such as freezing brewed coffee, frozen coffee grounds, and ground whole beans after freezing, assessing their impact on flavor and chemical composition.
“Then we’ll see which ones taste good,” Wiley says. The team used a class coffee review sheet to record attributes such as acidity, bitterness, sweetness and overall flavor, combining the results with FTIR analysis to determine how storage affected the taste.
Wiley acknowledged that “good” is subjective. “Sometimes there is a group consensus. I think people like richer coffee, not watery,” he says.
Other student projects compared caffeine levels in different types of coffee, analyzed the effect of microwaving coffee on its chemical composition and flavor, and studied the differences between authentic and counterfeit coffee beans.
“We gave students some materials to look at in case they were interested,” says Justin Lavallée, director of Breakerspace and co-teacher of the class. “But mostly we told them to focus on something they wanted to learn more about.”
Drip, drip, drip
In addition to answering specific questions about coffee, students and teachers gained a deeper understanding of the beverage.
“Coffee is a complicated subject. There are thousands of molecules in the beans, which change as you roast and extract them,” says Grossman. “The number of ways you can engineer this set of molecules is profound, from where and how the coffee is grown, to how the cherries are then processed to get the beans, to how the beans are roasted and ground down to whatever brewing method you use. »
Dinesen learned this firsthand, discovering, for example, that darker roasts contain less caffeine than lighter roasts, dispelling a common misconception. “You can vary the coffee a lot, just based on the roast of the bean and the size of the grind,” she says. “It’s so easily manipulated, if that’s a word.”
In addition to learning more about the science and chemistry of coffee, Dinesen and McDonald learned new brewing techniques, such as using a pour cone. The two even incorporated coffee brewing and testing into their study routine, brewing coffee while tackling problems from another class.
“I would put my pour cone in my backpack with a Ziploc bag full of grounds, and we would go to the student center and take out the cone, a filter, and the coffee grounds,” McDonald says. “And then we were doing verses-overs while doing a P-set. We also tested different amounts of water. It was fun.
Tony Chen, a materials science and engineering student, reflected on the 3000 title – “Using Breakerspace to Make the Perfect Cup” – and whether creating a perfect cup is possible. “I don’t think there is a perfect cup because everyone has their own preferences. I don’t think I’ve reached mine yet,” he says.
Enthusiasm for the complexity of coffee and the process of discovery was exactly what Grossman hoped to inspire in his students. “What I liked best was also seeing them develop their own curiosity,” he says.
He remembers a moment early in the class when the students, after seeing a demonstration of the light microscope, saw the surface texture of an enlarged coffee bean, the mottled shades of color and the pattern in honeycomb of tiny irregular cells.
“They say, ‘Wait a second. What if we added hot water to the grounds while they are under the microscope? Would we see extraction? So they had hot water and ground coffee beans, and voilà, it was different. They could see the extraction there,” says Grossman. “It’s like they have an idea inspired by learning and they’re going to try it. I have seen this happen many, many times throughout the semester.