Whisking up a storm with Harvard’s hottest new food-science course
The idea behind a chocolate chip cookie is not typically discussed in Harvard University science courses, nor are the delectable desserts usually baked using physics and chemical formulas. But some Harvard students have recently ditched their kitchens in favor of the classroom, baking their cookies by submerging them in a vat of liquid nitrogen.
“[The liquid nitrogen] accelerates cooling and if you do it for the right amount of time, you’re able to take the heat off the outside,” Harvard teaching fellow Daniel Rosenberg told the Daily. “So when you cool it down, the outside is frozen and crisp while the inside is still molten because the heat doesn’t have time to escape.”
That is how cookies are made in Harvard’s new class, Science of the Physical Universe 27: Science and Cooking: From Haute Cuisine to Science of Soft Matter. Nearly 700 students signed up for just 300 spots in the course, which aims to teach students the scientific principles behind modern cuisine and uses the principles of molecular gastronomy to alter the chemical and physical structures of the ingredients.
Substances such as xantham gums and techniques such as spherification, for example, are used to achieve different textures and bring out different flavors in foods, Rosenberg said.
According to David Weitz, a professor of physics at Harvard’s School of Engineering and Applied Sciences and Department of Physics, the class grew out of a visit two years ago by Ferran Adriá, whose restaurant, El Bulli, was named the world’s best restaurant by the S.Pellegrino World’s 50 Best Restaurant list for the past four years.
“One of the [post-doctorates], Otger Campás, wanted to invite Adriá,” Weitz told the Daily. “I said that he’d never come, but he did. When he was here, he was like a rock star; afterwards, we asked what we can do, and he said that he wanted to teach a course, and from then on it started.”
Adriá is not the only famous chef involved in the course. Some of the other visiting lecturers include Wyley Dufresne of New York’s wd~50, Grant Achatz of Alinea, Dan Barber of Blue Hill Farm, José Andrés of Jaleo and the White House’s pastry chef, Bill Yosses.
Every Tuesday, students in the class attend a laboratory demonstration by one of the 12 chefs, and on the following Thursday, Weiz and Michael Brenner, Harvard professor of applied mathmatics and physics, take turns explaining the scientific principles involved: phase changes, calorie interactions, viscosity, Coulomb’s Law and gelatin and foam stabilizations, among others.
Some of these concepts can be intimidating, but for the most part, they are usually straightforward, food blogger and Harvard Culinary Society President Lingbo Li, a senior, told the Daily.
“For the most part, the recipes are pretty standard,” Li said. “Although you’re in kind of a weird lab setting — you’re dealing with burners and portable stoves — you can still extricate the recipe pretty much like everything else.”
“The teachers really emphasize the science part of it with equations,” Li added, “and you do some experimental stuff like measuring the elasticity, or you might see how the mass of a purified liquid changes based on how long you leave it in a solution.”
Though the class is unusual in its course subject, Weitz stressed that it is as challenging as any other science course.
“The workload is as much work as most science classes here but much more fun,” Weitz said. “How often do you have a science class where you eat your experiment?”
Though the experiments can become bizarre — like the times the students turned fruit purees into gels and deconstructed strawberries into powder — most of the material is usually more academic than one would think.
“You get to understand that meat gets really dry when you cook it to a too-high temperature, for example,” Li said. “But you wouldn’t know the scientific reasoning behind that if you don’t understand the molecular structure of meat.”
One week, the class was designed for aspiring plant microbiologists and led by Barber (Tufts ’92), who was named the top chef in America by the James Beard Foundation in 2009 and was listed as one of Time Magazine’s Most Influential People that year.
Barber’s interest is in the “seed-to-kitchen” component of cooking, and he uses many natural ingredients to enhance his dishes. One way of manipulating an ingredient, Barber explained, is by infusing a root vegetable like celtuse with flavor.
“We experiment with a bunch of things … using a soil as a vector,” Barber told the Daily. “Then we can take crushed almonds and plant that with the vegetable, and with the process of osmosis, you get a carrot with an impregnated flavor of almond.”
Because of Barber’s unique teaching methods, students do not necessarily need to have much scientific knoweledge in order to participate, Li said. At the same time, the class is a great opportunity for science students to get out of their comfort zones, she said.
“You could learn about how new farming techs can support a world population in the future,” she said. “It’s definitely something that can be applied to the real world, and in a basic level inspires students to be more thoughtful in what [may or] may not work in the culinary society.”
Li and Weitz both predict that the course will continue its success at Harvard and that the practice will start popping up elsewhere, as well.
“It will be offered again next fall,” Weitz “said. “We’ll still try and improve it. [Adriá] has signed on and has decided to spend more time here.”
– Jon Cheng