On November 19, 2013 the Midland Section of the American Chemical Society and Chef Aaron Gaertner of the Saginaw Career Complex co-sponsored Loco for Cocoa. This free science café offered four action-packed segments, each followed by rich and tasty samples for all. Each segment began with Dr. Gina Malczewski providing the relevant background chemistry followed by a cooking lesson from Chef Aaron. Approximately 60 people were in attendance, including MCTV who recorded the event.
Pointing to a projected image of a capsaicin molecule, Gina summoned audience participation to identify atoms. Explaining the molecule’s medicinal use, she pointed out chemical bonds and hydrophobic and hydrophilic portions of the structure. She proceeded with an overview of the culinary history of the cacao plant, leading to chocolate as we currently know it. The lesson took us back to nuns in the 1500s experimenting with spices and chocolate to enhance the palatability of an old turkey. Success of their endeavor resulted in mole (pronounced mo-lay) sauce, versions of which are enjoyed around the world today.
Chef Aaron then treated our senses to the aromatic sizzle of garlic, onion and spices, using preparation of a simple mole sauce to explain the concept of molecular gastronomy and today’s movement back toward pure, whole artisan foods. He explained caramelization, the importance of fond and deglazing, as well as use of tomato to provide the dish’s acid component.
His surprising move to finish the preparation with addition of 70% cacao chocolate provided richness, sheen, flavor and body to the sauce. Periodically he held the pan under a camera which projected the image onto a large screen, allowing a view of the wonder teasing our olfactory receptors. Several sous-chefs deftly distributed paper-plated crackers, piled generously with mole sauce and chopped chicken, to audience members.
Next, Gina and Aaron moved on to discuss drinkable chocolate, star of Loco for Cocoa’s second segment. Gina’s chemistry lesson covered terms such as roasting, fermenting, alkalization and tempering, as applied to cocoa beans for illustration of concepts. Projecting onscreen images of theobromine, caffeine, theophylline, phenylethylamine, and other major molecules in chocolate, she pointed out various aspects of their structures and any known physiological impact of each.
Aaron, a classically trained French chef, poured cream into a pan, grated cinnamon, added various spices, cocoa, honey and a dash of Sriracha sauce. Finally, he melted in 70% cacao chocolate, noting that you don’t need much. A little goes a long way when targeting richness, versus sweetness. Chef Aaron explained that this hot chocolate affects each part of the palate while engaging the sense of smell. The audience was able to appreciate this while sampling petite cups of the smooth chocolate liquid. Its rich cocoa flavor was well complemented with a slight spiciness and satisfying hint of sweetness.
The chemist-chef duo’s third segment, baconated chocolate, provided an opportunity to further discuss cooking-chemistry terminology, such as tempering and emulsification. We learned that chocolate, if not properly tempered, will exhibit an undesirable white coating known as bloom—the result of sugar or fat separating out from the chocolate. Gina explained how one could easily experiment to determine which type of bloom a chocolate has by adding a drop of water.
Emulsifiers, such as lecithin, were discussed in light of their water-loving and water-hating attributes which function to bring unlike things, such as water and fat, together. The concept was beautifully displayed by a bottle containing water and oil that Gina passed around to the audience. This was followed by another that also contained lecithin, which visibly unified the hydrophobic and hydrophilic components. A third bottle was then distributed which illustrated how an ionic substance, such as salt, could interfere with the emulsifier, separating the water and oil back into discrete layers.
While baconating a rich melted chocolate, Aaron discussed seizing, an important phenomenon to avoid when working with chocolate. Seizing, which causes the wetted sugar molecules to clump together, can occur by introducing even a small amount of water, such as steam from a double boiler. Thankfully, our resourceful chef used plain chocolate chips to demonstrate the grainy, clumpy results of seizing as we sampled his smoothly solidified chocolate with crispy bits of maple-smoked bacon.
The fourth and final segment enlightened attendees with a brief history of how chocolate chip cookies came into existence, along with an overview of the various forms of chocolate known today. As attendees nibbled lightly-crisped chocolate chip cookies baked prior to the event, Gina and Aaron closed with a recap of major points and answered questions from their very satisfied audience.