At Feng Chia University (FCU), every Chemical Engineering student must take 13 credit hours of elective courses. There are many elective courses offered in the Chemical Engineering department such as paint chemistry, polymer science, and nanotechnology. One of the most interesting elective courses, the one I chose this semester, is Fermentation Engineering. We were given a term project in class, to make soy sauce using the traditional method, fermentation.
In class, we were given a big bag that contained an empty glass bottle with boiled black beans inside, a small pack of Aspergillus fungus, and a big packet of fine salt. The first step in making our soy sauce was to choose the best black beans. We had been taught that choosing good quality beans plays an important role in the fermentation process. Good quality beans have a stable level of protein, which helps the breakdown of proteins in the fermenting process. Good quality beans are what give the sauce its complexity. After choosing the best black beans, we washed and soaked the beans overnight. Then we steamed the black beans in a pressure cooker at a certain temperature. This steaming process is complicated and requires special knowledge. This was the step that we didn't do by ourselves; we were helped by the master students.
|All photos by the author|
The boiled black beans were put into a glass bottle and left for one to two days to dry (the beans were wet due to water vapor). Two days later, Aspergillus spores were mixed in with the boiled black beans. We had to make sure every black bean was covered with the spores. Later, the spores will grow into a fungus. Aspergillus fungus is a genus of fungus that is used for fermenting. This fungus is also used to propagate Koji mold, one of the most important elements in making soy sauce. Koji plays a crucial role in breaking down the proteins in the black bean “mash.” Three weeks later, when the Aspergillus mold had grown on the black bean mash, we washed it with purified drinking water to remove the mold on the surface of the beans. After removing all the mold, we covered the surface of the beans with a huge amount of fine salt and left the culture to brew. We added salt to the culture because it will act as a preservative to preserve the culture. It will also control the propagation of bacteria during the brewing process.
We students were divided into groups for this term project. In my group, I was responsible for observing the culture throughout the semester. We need to present a full report at the end of the semester. I have been keeping the culture in my dorm room and observing the culture on and off. The culture must be left for fermentation for several months. As I have made my observations, I have seen the beans slowly turned to reddish brown mash, but I haven’t seen any liquid yet. The liquid will be our product because it will be the soy sauce that we want at the end of the semester. An eccentric smell spreads over my room every time I open the cap of the glass bottle. I think this means that something is happening – something good, I hope.
I have discovered that Fermentation Engineering is an interesting course. The goal of the course is to describe the process and related techniques used for achieving high product yields by the large cultivation of living cells. In this course, we have been taught that many commercial products nowadays are produced by fermentation such as fermented milk, cheese, and yogurt-based beverages. There are some students from business college in the class, too. This could be a precious chance for them to learn a new way to make money.
Every FCU student has to earn elective course credits in addition to the core courses in their department. Fermentation Engineering is a compelling course because students can get hands-on experience in class. Hands-on experience is critical in skills development and career development. With this experience, we can discover what field we are interested in. Therefore, I highly recommend this course for all Feng Chia University students, no matter what their major is.