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Freshmen Chemical Engineers have the Sweetest Class on Campus

Noelle Comolli, PhD
Noelle Comolli, PhD

Who: Noelle Comolli, PhD, department chair and associate professor of Chemical Engineering

What: A course for first-year ChE majors, introducing them to the field through the fun and relatable process of making chocolate. Dr. Comolli says, “I want to teach them the different pieces (unit operations) of a process and how they link together, and chocolate is perfect for demonstrating this.”

A Trip to Hershey: Before launching the course, Dr. Comolli visited the Hershey Chocolate Factory and spent a full day in “Chocolate 101” with chocolate engineers.

More about the course: Dividing the class periods into a combination of lectures and hands on labs, Dr. Comolli begins by exposing students to the chocolate-making process at a basic level, teaching the chemistry behind it and how the process fits into an engineering model. Labs include:

  • Looking at sugar fermentation
  • Observing chocolate flow rates 
  • Testing chocolate hardness


CHE Concept

Chocolate Process

“Unit Operations”/ Chemical Processes

The overall process

Mass Balances/ Reactors


Fluid Mechanics

Chocolate liquor

Heat and Mass Transfer


Material Properties


Process Safety

Food safety quality control


Product unit packaging

Ethics & Catholic Social Teaching

Bean harvesting/At the farm/
Fair Trade


Life Cycle Analysis

A Tasty topic: “Using a fun process allows for more discussion of topics that students often view as boring, such as process safety and ethics.” One of the course assignments is an ethics paper regarding the marketing of chocolate to children given the epidemic of childhood obesity. Another topic is fair trade regulations, a practice that the University is committed to when purchasing products.

Final project: Students are divided into groups and given pure baker’s chocolate to create tasty Villanova-themed treats based on the material taught in class. A combination of sweeteners and milk fats can be added to their unique recipes to improve flavor. When creating their chocolates, students are encouraged to think about the cost, quality, ethics and sustainability of the process and final product. At the end of the semester, each team explains its process and provides samples to their classmates. While the final product is judged on taste, it is important that students understand the chemistry behind their creations and are able to explain why a product may not have turned out as planned (taste or texture-wise).