While not all of the world鈥檚 top chefs consider themselves scientists, many approach cooking with a scientific mindset. And it鈥檚 hardly surprising why. In chemistry professor Dr. Susan Green鈥檚 course Food Chemistry, it quickly becomes apparent that knowing even a little bit about the making of your favorite meal can have an outsized effect on its texture, appearance, flavor, and aroma.
From the science behind fluffy pancakes to the 鈥渕agic鈥 of self-hardening chocolate sauce for ice cream, students in the course gain valuable experience cooking for themselves (and often their friends and family). But it鈥檚 not all about creating a 鈥渂etter鈥 meal. Green and her action-packed food demos also work together to teach students how to thoughtfully navigate conversations at the intersection of local foodways, social justice, and environmental chemistry.
Inspiration for this course comes from the adage 鈥淣ever trust a chemist who can鈥檛 cook.鈥 Can an understanding of food chemistry truly reveal the worth of a chemist?
That鈥檚 a truism that many chemists share among themselves to acknowledge the fact that if you can follow a recipe and make a cake, you can also probably synthesize a diol (an organic compound). And while it is a fun saying, I really do believe that an understanding of food chemistry can tell you quite a bit about who someone is as a chemist. For instance, if you can follow a procedure in a journal article to synthesize something, you can follow a recipe. So chemists tend to be recipe followers for the most part. Although, I do think it鈥檚 important to note that cooking and baking are two different things, right? People who bake tend to follow rules, and people who cook tend to not follow rules as much. I always read the whole recipe (or procedure) first because I鈥檝e learned the hard way from doing experiments that you always need to have an idea of what鈥檚 coming next.
There鈥檚 also the idiom 鈥淣othing can account for taste,鈥 but, scientifically speaking, people do taste things differently. How should that inform our conversations around food?
One of the really fun demos that we do in class is having students taste-test strips containing thirty micrograms of phenylthiourea. Typically, an unfortunate quarter of students will find it extremely bitter; half will find it mildly bitter; and the rest find it completely tasteless. And so, together, as a class, we learn that things are fundamentally not the same when we put them in our mouth. And once you understand that, it鈥檚 much easier to have respectful conversations about how something should taste, how you should cook something, and how you should eat something.
Food Chemistry has been a hit with non-science majors and advanced chemists. Why does it prove so engaging for both?
Food is universal. Everybody eats, whether you cook or not. And so, I can sneak some chemistry in there when we鈥檙e talking about food, right? For my chemistry majors who have had several years of study behind them, they learn how to apply what they鈥檝e learned and have some fun. They think about what making scones has to do with acid-based chemistry and all these very technical things. And then I have the nonmajors who are like, 鈥淲ow! I know what those squiggly line drawings now mean. I can tell you that this is a carbon, and I can tell you that this is a stereocenter.鈥 It鈥檚 so fun to watch political science majors and art majors suddenly geeking out in a chemistry lab.
Your course features a variety of cooking demonstrations and lab experiments. What鈥檚 one of your favorites?
Oh, that has to be bomb calorimetry鈥攖hat鈥檚 the really cool one. On food wrappers and packaging, companies always list the number of calories in an item. Well, the way that food scientists measure that is by literally blowing it up. By blowing it up, they can measure how much energy is released and note the calories. In our course, we have students bring in a food item that they鈥檝e created in their own kitchen, and we take it into the physical chemistry lab and put it in the bomb calorimeter. We learn how to wire it up, let it explode, and then measure the energy that鈥檚 produced. Not only are students getting to do an advanced chemistry experiment; they鈥檙e getting to do so on a food creation of their own making鈥攚hether that鈥檚 pulled pork, onigiri, or sourdough bread.
Your course often incorporates local resources and food pathways. What鈥檚 it like teaching this course in Minnesota and the Twin Cities?
Minnesota offers such interesting case studies which showcase how an understanding of food chemistry can open eyes to how local food pathways work. One of the best lectures in this class actually comes from my fellow chemistry professor Ron Brisbois, a descendant of the White Earth Band of Ojibwe in northern Minnesota. Ron talks all about wild rice and what it means to his family. And then we talk about how wild rice grows, how the plant is impacted by sulfate in lakes, and how mining projects can impact that sulfate concentration. When levels get too high, it causes wild rice to die off. An understanding of that science and local traditions helps students understand why many Native peoples are working with environmentalists to protect wild rice lakes across northern Minnesota.
