Harvard Cooking Classes: Undergrads Take on Science Behind Food
After a semester studying the science behind food, students in Harvard’s popular cooking class test out hot ice cream, glow in the dark gummy bears, and other unusual foods.
For food fanatics, it has been one of the great culinary challenges of the last couple of decades: how do you make a tender noodle that mimics traditional pasta without using wheat?
Many have tried, and many have failed. Many others have gotten close, but often the specimen either falls apart as it’s cooking in boiling water or is so rubbery that it’s not worth eating. So when award winning chef Barbara Lynch presented the challenge to a group of Harvard undergrads this past semester, three industrious young students jumped at the chance to study the problem as part of their research project for the school’s “ Science and Cooking” class.
Gluten-free noodles are often made with some sort of gelling agent like xanthan gum to bind the ingredients together. (In regular pasta, the gluten from wheat creates a protein matrix that holds everything in place.) But which would be easiest to cook? Which would produce the best mouth feel? The trio—senior Jennifer Kusma, junior Michelle Burschtin, and junior Erica Seidel—created five sorghum flour-based doughs, each with a different agent, and set about testing each one.
They evaluated each dough by blind taste test (10 lucky friends got to try all five pastas) and by calculating the elasticity of each sample (accomplished by attaching weights to the cooked noodle and measuring how far they stretched). The results were compared to store-bought wheat pasta, and the group found that both the agar agar and locust bean gum created dough that acted the most like the more traditional macaronis.
But, their project wasn’t the only successful one to come out of the class, which was designed to teach science principles through food. It was just one of about 125 projects that students put together throughout the semester. The experiments yielded a variety of culinary breakthroughs that may be coming soon to a restaurant near you.
Hot ice cream? Check. Just add methyl cellulose, a thickener that can withstand high temperatures. Heat-resistant chocolate? No problem. A naturally occurring enzyme called transglutaminase can keep the chocolate from melting. Glow in the dark gummy bears? Easy. Just add a little quinine.
“There were huge numbers of really creative projects that could be used in some way,” said Michael Brenner, a professor of applied mathematics and physics at Harvard. “The cooking was experimental and rooted in many of the science principles we studied all semester.” The class went so well, in fact, that Harvard will be offering it again next year with the help of one of its key sponsors, the Alicia Foundation, an organization dedicated to food and science.
One group of students tackled an important party question. Why does guacamole brown and what can we do about it?
The answer lies in polyphenol oxidase, an enzyme that combines with oxygen to speed up cellular decomposition. The students found that by leaving the avocados in their peels and giving them a hot water bath for a few minutes denatured the enzyme. The guacamole stayed a nice green even after sitting out for a while.
Another student figured out how to make what is essentially hot jello. Bethania Bacigalupe, a sophomore from Newton, Massachusetts, looked at the properties of soup stocks—which use the gelatin from animal bones coaxed out by water and heat—and set up a series of experiments designed to explore how to keep gelatin stable at high temperatures.
“The chefs from wd-50 wanted a solid soup stock or gelee that doesn’t melt when it’s heated up,” said Bacigalupe, referring to the restaurant owned by one of the course’s guest lecturers, Wylie Dufresne. “They wanted to make a solid soup that tastes like and has everything a soup would have but with a different texture.”
Bacigalupe used transglutaminase—also known as meat glue—to solidify the bonds between the animal proteins in the stock. It made for a heat resistant gel that could withstand temperatures of up to 176 degrees Fahrenheit. And, she checked the pH of the stock to make sure that it didn’t interfere with the enzyme.
Though she worked on a very small slice of food science, Bacigalupe takes a more meta view of the class and her experiment.
“You’re deconstructing taste and flavors … and creating a different experience,” Bacigalupe said. “The goal here was to be able to make a hot consomme that was solid, but the technique can give you a lot of options. You can flavor this any way you want.”
Laura Colarusso is a reporter at The Daily Beast. She previously worked as a senior news editor at Talking Points Memo. She has also written for The Boston Globe, The Star-Ledger (Newark), AOL and New Jersey Monthly Magazine.