Researchers found that kombucha made from green and oolong teas showed the strongest antioxidant activity, while each tea type produced a different chemical and sensory profile during fermentation.
By yourNEWS Media Newsroom
The type of tea used to brew kombucha can significantly change the fermented drink’s chemical makeup, aroma and antioxidant activity, according to a new study from researchers at Wrocław Medical University and Wrocław University of Environmental and Life Sciences.
The study, published in Food Chemistry, compared kombucha made from black, green, white, oolong and pu-erh teas under the same fermentation conditions. Researchers found that green tea and oolong tea kombuchas showed the highest biological activity, including the strongest ability to neutralize free radicals, according to a June 23, 2026, press release from Wrocław Medical University.
Kombucha is made by fermenting sweetened tea with a SCOBY, a symbiotic culture of bacteria and yeast. During fermentation, yeast converts sugar into alcohol and carbon dioxide, while bacteria produce organic acids, including acetic acid and gluconic acid. Those acids help give kombucha its sour flavor.
The fermentation process also changes tea’s naturally occurring compounds, including polyphenols and volatile aromatic compounds. Those changes help determine the drink’s antioxidant profile, flavor and aroma.
Using advanced chromatographic methods and mass spectrometry, researchers tracked hundreds of chemical compounds as fermentation progressed. They found that compounds linked to floral and fruity aromas, including linalool and 2-phenylethanol, increased during fermentation. Other compounds that were present in freshly brewed tea disappeared.
The findings support the view that kombucha is not a single uniform beverage. Instead, the tea used as the base ingredient plays a major role in shaping the final product.
Green tea kombucha developed fresher, more vegetal aromas, while oolong tea kombucha produced stronger floral and fruity notes. Black tea and pu-erh kombuchas had richer, earthier aromas and more pronounced fermentation characteristics.
Associate Professor Helena Moreira, PhD, a study co-author from Wrocław Medical University’s Department of Basic Medical Sciences and Immunology, said green and oolong tea produced especially notable results.
“Particularly interesting results were obtained for kombuchas prepared from green and oolong teas, which demonstrated the highest biological potential,” Moreira said.
Researchers said the laboratory findings do not prove specific health benefits in humans and that clinical studies are needed to determine how different kombucha varieties may affect health.
Still, the antioxidant activity observed in the study adds to long-standing interest in kombucha as a health-promoting fermented drink. Traditional Chinese medicine has referred to kombucha as an “immortal health elixir,” and food scientists have described it as a beverage containing bioactive compounds.
The study also reinforces the importance of fermentation conditions and raw material selection. Books on kombucha and fermented foods have noted that fermentation consumes sugar and generates beneficial acids and metabolites. They also emphasize that black, green and oolong teas provide nutrients that support a healthy SCOBY culture.
Some herbal infusions may be less suitable for kombucha brewing because high levels of volatile oils can interfere with SCOBY growth, making tea selection an important factor for both home brewers and commercial producers.
“Fermented foods are currently at the center of scientific interest because they combine traditional technologies with a modern approach to health and nutrition,” Moreira said.
The researchers said the most notable discovery was how much fermentation changed the beverage and how strongly those changes depended on the tea base.
“The most surprising aspect was the scale of changes occurring during fermentation and how strongly they depended on the type of tea used,” Moreira said.
The study adds to growing interest in fermented foods and drinks as sources of bioactive compounds. For consumers, the findings suggest that kombucha made from different teas may offer different antioxidant profiles, flavors and aromas.
Researchers said future clinical studies will be needed to determine whether kombucha made from specific tea types produces measurable health effects in people.
Source: Natural News
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