The art and science of chocolate

Erin Mullin '17 (L) and Yihan Gao '19 melt chocolate in the Chocolate Lab

By Keely Savoie

Valentine’s Day often celebrates the capricious flights of Cupid’s arrows — and the resulting joys of unlikely unions — as peculiar as they are perfect. Perhaps that’s why the Chocolate Lab at Mount Holyoke College is so popular. It is the most improbable union of physics and material science, love and chocolate.

The Chocolate Lab is an updated twist on Mount Holyoke’s historic connection to Valentine’s Day that began with Esther Howland ’47, who is credited with beginning the Valentine’s Day card tradition. Those original cards can be sent as e-cards today.

The hands-on workshop gives students, faculty, staff and families the opportunity to make chocolate molds and then fill them with melted chocolate to create custom chocolate treats for loved ones.

Katherine Aidala, chair of the physics department, designed the lab to be accessible to the entire MHC community.

“The idea is that anyone — whether they have a physics background or not — can learn a little bit about computer-aided design, 3-D printing and the material science of tempering chocolate,” she said. 

The lab is held in the Mount Holyoke Makerspace and takes place in two sessions, although attending both is not necessary.. During the first session, chocolate-makers learn the basics of computer-aided design and 3-D printing and create the shapes — hearts or coin-shaped discs — with custom lettering or designs. 

The Makerspace coordinator, Shani Mensing ’15, and Makerspace assistants then print them on the 3-D printer to ready them for mold-making. This is done using a thermal vacuum former: a thin sheet of plastic that is heated over the 3-D printed objects. The heat forms a vacuum, which draws the forms into the plastic and forms a mold.

The next session focuses on melting — or tempering — the chocolate in a specific way to form the molecular structure that yields a hard, shiny and stable candy.

“People don’t think a lot about the material science of the things they cook,” said Aidala, “The chocolate you get at the store is correctly tempered, and to get that crystal structure you have to bring the chocolate through a complete thermodynamic cycle.”

One year Aidala printed the desired crystal molecule, theobromine, on a mold. Others have printed the Mount Holyoke logo, or the names of partners or friends. Some molds work better than others and sometimes the chocolate doesn’t quite set. But the sweet thing about the Chocolate Lab is that it doesn’t have to be perfect.

“If your chocolate breaks, or you don’t get the right crystal, it still tastes great,” Aidala said. “At the end of the day, you’re still eating chocolate.”

Find your sweet spot. Learn More.