As Paly parent Tam Phung opens up a bottle of her homemade kombucha, the aroma of fresh ginger, honey, oranges and apples that she had infused into the tea days prior filled the air.

After two weeks of fermentation and carbonation, her finished product is finally ready for enjoyment.

Kombucha, a fermented tea, has become increasingly popular not only in the food industry, but at Paly as well.

While some purchase kombucha at conventional grocery stores, others in the Palo Alto community, such as Phung, have begun making their own kombucha at home.

“I started when a work colleague introduced me to the process and provided me with a starter kit — in other words, the starter symbiotic colony of bacteria and yeast (SCOBY),” Phang said.

According to Cultures for Health, SCOBY is a mother culture combined with tea and fermented during the kombucha-making process.

Since the preparation of the beverage involves bacteria colonies, many are wary of carrying out this practice at home, including Chemistry and Environmental Science teacher Alicia Szebert.

“I’ve always been concerned with the sterility of it because you’re growing bacteria. I haven’t grown my own kombucha, but I’ve always had intentions of (it) because I spend so much money on it.”

Alicia Szebert

Paly parent Josh Lehrer also distills his own kombucha.

“We had too many plums all at once from a tree and noticed the white yeast bloom on the skins,” Lehrer said. “(I) thought it would be fun to let it ferment and (I) looked up how to make country wine. Then, I tried making mead from honey, and then fermenting pickles, Sauerkraut and kombucha. It was pretty easy, though, (I) just take some old kombucha and add cooled tea and some sugar or fruit juice. Then I put it into a clean beer bottle, applied a fastener to close the bottle and then (wait) a couple weeks.”

Phung’s process is slightly different as it includes the use of a SCOBY.

“The process takes about two weeks,” Phung said. “The first week is the fermentation process with SCOBY, tea and sugar. The second week is infusion –– remove the SCOBY and mix tea with spices, fruit and more for about one week.”

During fermentation, the bacteria on the SCOBY reproduce with exposure to oxygen. When the tea is fermented for longer, it tastes more like vinegar and is less sweet. During the carbonation process, the bottles are closed so carbon dioxide produced from yeast does not escape. These carbon dioxide bubbles cause the tea to be fizzy. The process can be time consuming, especially as some recipes call for fermentation to happen over 30 days. Because of this, Phung stopped brewing kombucha at home.

“I was making kombucha for about six months but stopped because it was time consuming (when) going to the store to buy tea,” Phung said. “I wasn’t drinking enough of it, and also my travels would interfere (when) fermentation time would be longer than ideal and then (the) tea would be overly fermented.”

However, Phung said she still sees several advantages to home-brewed kombucha.

“The reason I did home-brewed kombucha is because it is cheaper than buying at the store, and I also liked (experimenting) with my own flavors (and) infusions.”

Tam Phung

Lehrer also find the process of making kombucha to be beneficial, especially since he was captivated by the fermentation process.

“It was fun to make something at home from scratch, be able to tinker with the ingredients and also be able to wait until there was the carbonation level that I wanted,” Lehrer said. “It was fun because it was like doing science experiments you could eat or drink, and bottling was also pretty cool.”