An Edible Approach to Materials Science: Investigating Heat Treatment and Phase Transformations with Chocolate

An engaging undergraduate lab was created that introduces students to core concepts of heat treatment and phase transformations in materials science through the use of chocolate as a model system. The experiment parallels the thermal processing of steels by examining how different cooling and reheating procedures affect the crystal structure and resulting properties of chocolate. Students perform heat treatments such as controlled tempering, quenching, and annealing to observe the formation of various cocoa butter polymorphs. Through visual, textural, and flavor analysis, students connect the microstructural changes in chocolate to analogous transformations in steels, including the development of phases and the impact on mechanical and physical properties. By linking an everyday material to foundational concepts in metallurgy, the laboratory enhances student engagement while demonstrating that learning about phase transformations can be both educational and enjoyable