PhD in Chocolate

[by Naveen]


a model of the solar system, constructed by master chocolatier Enric Rovira, one of the inspirations for this post

My latest obsession has been the science of chocolate. After several literature searches and interviews with people about the transformation from cocoa pods to chocolate bar, I'm starting to get a sense of feasible thesis topics, which would be both scientifically interesting and industrially relevant (as well as delicious). Two main frontiers in the chocolate world that can be explored from a soft matter physics perspective seem to be:

1. Design a simple, reliable "temper-meter." By melting and cooling molten chocolate in a specific way, chocolate makers can create a solid bar that is glossy on the surface and breaks cleanly. If this procedure isn't done right, the chocolate can be crumbly and develop an ugly whitish coating on the surface, called bloom. The main difference relates to how the cocoa fat molecules are stacked within the chocolate: well-tempered chocolate has all these molecules packed tightly together. Unfortunately, the only way to determine this conclusively is with x-ray diffraction, which isn't especially convenient for artisan chocolate makers. A more common method is to measure the temperature of the chocolate over time as it cools, which works okay, but apparently there is still considerable room for improvement.
2. Glossy coated almonds (or nibs, cocoa beans, etc.). In a technique known as panning, the nuts are placed in a large rotating vat and molten chocolate is slowly drizzled over them. As the nuts tumble around, a layer of chocolate gradually develops around each nut. Somewhat surprisingly, the resulting coating is smooth and fairly resistant to bloom, despite not undergoing the specific tempering process. However, it's still tricky to attain a glossy, rather than matte, surface on the product, so additional coatings are typically used in the industry.

Armed with my physics knowledge of mechanics, electricity and magnetism, acoustics, and (high-school level) chemistry, I think that I can discover some interesting things while I pursue these problems. If I'm incredibly lucky, I could help solve some major problems in the chocolate industry. At worst, I'll have fun playing around with chocolate.