In the Chemist's Kitchen: Teaching Science with Food
by William Sweet
In Patricia O’Hara’s popular new introductory chemistry course, the periodic table of elements includes nitrogen, mozzarella and prosciutto.
“Molecular Gastronomy and Food Science: From Test Tubes to Taste Buds” looks like a cross between a cooking class and a science lab—and that’s the point, said O’Hara, the Amanda and Lisa Cross Professor of Chemistry.
Liquid nitrogen puts a new spin on cuisine: Voila, flash-frozen crumbled prosciutto.
(See more photos from the class on Flickr.)
“I love science, and I really want my students to love it too, but so often they don’t see the relevance of the topics I’m teaching to their lives,” she said.
She sought inspiration from a subject that gets practically everyone’s attention: “I felt there could not be a better vehicle than food. Essentially the act of eating, physically, is a combustion reaction.”
“If you have ‘This is hydrochloric acid. This is sodium hydroxide. Let’s mix them together. Let’s take an indicator,’ that’s kind of boring,” she continued. “But what if you say, ‘Why is yogurt different than milk? What is it that is happening?’”
O’Hara has been traveling to Turkey to lead workshops on the science of olive oil since 2010. For her upcoming sabbatical year, she’ll spend six months teaching at Istanbul’s Boğaziçi University, and then she and her husband, Richard Blatchly (a chemistry professor at Keene State College) will depart to South Africa to observe the spring olive harvest.
But “Molecular Gastronomy” at Amherst is her first opportunity to put non-science majors in a lab setting. “Having it be lab-based is really important to me,” she said, “because that’s the real unique quality that science has that it shares with art and theater. In some sense it’s a performing art.”
“The chemistry lab is like a kitchen,” she noted. “It has counters; it has sinks; it has electricity for gadgets; it has good lighting; it has stools, refrigerators, hotplates, stirring machines.”
The class revolves around the chemistry of nutrition, but it also focuses on the experience of food. According to the course description, students “examine our core requirements for food as we eat to live, and some of the cultural, social, historical and culinary dimensions as we live to eat.”
The race is on to create a science-based appetizer.
(See more photos from the class on Flickr.)
Most of the course explores modernist cuisine, the science-based reconstruction of fine cooking advanced by physicist, inventor, businessman and amateur chef Nathan Myhrvold. Students read roughly a chapter per week from Myhrvold’s Modernist Cuisine: The Art and Science of Cooking, which O’Hara praises as a cookbook “full of biology [and] full of nutrition,” featuring diagrams and detailed scientific explanations as well as recipes.
O’Hara teaches that the human invention of cooking had three important purposes: to render tough foods chewable, to kill anything in the food that might make us sick and to preserve the food longer. As technology now renders this less necessary, modernist chefs look at new ways to prepare food. For example, diners at high-end restaurants will pay top dollar to have ice cream made at their table using liquid nitrogen. O’Hara does a version of fast-frozen ice cream herself: in her other role as dean of new students, she’s prepared it at parties in each of the first-year dorms.
Her “Molecular Gastronomy” students tried a high-tech version of a very old kind of cryocuisine (that is, food-freezing) familiar to New Englanders: “sugar on snow.” In the kitchen lab, they compared the qualities of hot maple sugar as it was poured on ordinary ice, dry ice (solid carbon dioxide) and liquid nitrogen. While the ordinary ice produced the familiar sweet treat, the syrup descended into a congealed puddle beneath the dry ice. The liquid nitrogen put on a spectacular show of bubbling fog, leaving an amber-clear cluster of frozen sap crystals that melted in one’s mouth.
Reviews varied among students, several of whom had never before tried maple syrup, let alone sugar on snow.
“I’m a fan of goo, so I like the dry ice,” said Elena Villafana ’14.
Students eat this all up, literally and figuratively. The class filled up quickly and has excellent attendance, particularly for one that convenes at 8:30 a.m., the professor said.
Allison Merz ’14 explains part of the appeal: “There is a strict ‘no eating or drinking’ policy in every other lab course, but here we can eat our experiments.”
“Students come to me with a real passionate interest in just learning more about food,” O’Hara said. They “want to eat without pesticides and eat local foods on the one hand, and on the other hand … learn techniques of what is called the modernist cuisine.”
The cryocuisine lessons culminated in a cooking competition straight out Iron Chef: given ingredients including prosciutto, mozzarella balls, tomatoes and fruit, lab partners were challenged to create an appetizer in 20 minutes.
Amherst's only chemistry lab with a taste test: the judges convene. Presentation matters.
They donned safety gloves and set to work, grinding, slicing, arranging. In a new twist on fondue, students dipped ingredients in liquid nitrogen to freeze them, with varying degrees of success.
“We could put some cheese in it…”
“Drizzle that on top…”
“I feel like I’m on Top Chef.”
Then came the taste test.
“I liked the pineapple flavored with the melon,” said Merz. “That was really a special combination. It chilled well; the other fruits were totally frozen.”
As students nibbled at their lab work, O’Hara polled each team about the preferred elements for their next experiment.“Do you want seafood or steak?” she asked.
Photo credit: Rob Mattson and Bill Sweet