SCOBY Science - Fermentation and Kombucha for the Science Fair

Interested in consumer and food science, this middle school student turned a fizzy kombucha project into an exploration of how biofilms make fermentation possible.

Extra Credit for the Middle School Science Fair

At Lancaster Country Day School in Lancaster, PA, students in the 7th and 8th grade are required to participate in the school's annual science fair. Students can earn extra credit if they also participate in one of the local area fairs, either the PA Junior Academy of Science (PJAS) or the North Museum Science and Engineering Fair (NMSEF).

Tastes Like Science!

For his 8th-grade project, Gabe chose What Sugar And Tea Does a Kombucha Biofilm Prefer?, a chemistry and food science project that involves making homemade kombucha to explore the role of biofilm, or a symbiotic culture of bacteria and yeast (SCOBY), in the process.

Gabe talked with us about his project and experience at the science fair.

The Science of Kombucha

Were you looking specifically for a food science project?

"I first got interested in consumer science last year. I did a project on ripening bananas, and I really liked the research behind it and how the chemistry of ripening worked. I wanted to do an experiment in consumer science again this year because I love cooking. I love making food for my family, so I thought that a food-related science project would be really fun. "

What drew you to the kombucha project?

"It was in consumer and food science, and it was about fermentation, which I am really interested in. Kombucha is also one of my favorite drinks, but I had never made it before. "

Tell us a bit about your project and how it went.

"For my experiment, I had to ferment five types of tea (black, oolong, green, white, and herbal) over the span of one month and test the sugar content, pH levels, and hydrogen concentration once every week. The results were pretty surprising to me. I thought that the sugar content would increase as the tea fermented, but, in most teas, the sugar content decreased. The biofilm was eating the sugar as it grew."

What was the most challenging part of the project?

"Though I am very interested in fermentation, I had little knowledge of the science behind it before doing this project."

What was the most rewarding or exciting part of the project?

"The most rewarding part of the project was knowing that I now have a better knowledge of fermentation. I had a great time getting to do this project."

You weren't able to try the kombucha you made?

"Due to the fact that there are a lot of bacteria in a SCOBY biofilm, my family and I did not drink the kombucha!"

Would you make kombucha again?

"Yes, I would definitely make it again, and maybe be able to taste the kombucha!"

What's next? Are you thinking about a "next" science project already?

"I have not thought of a next science fair project, but it will most likely be in consumer science!"

What do you enjoy most about the science fair?

"I enjoy the research behind the project and getting a better understanding of how the science works, like fermentation and ripening, for example. Science is one of my favorite subjects, and I really enjoy doing science fairs like NMSEF and will most likely attend it next year!"

Are you considering a future in STEM?

"My career goal is to study animal science and become a veterinarian."

Thank you to Gabe for sharing this story with Science Buddies. If you have a story about doing a Science Buddies project or how Science Buddies makes a difference in your classroom or program, reach out to us at [email protected].