The Kombucha Surprise: One Ingredient Dramatically Changes Its Chemistry and Health Potential

Tea choice significantly changes kombucha’s chemistry, flavor, and antioxidant potential, with green and oolong teas showing the strongest biological activity.

Kombucha has surged in popularity worldwide in recent years, but researchers are looking beyond its flavor to better understand its chemistry and possible health-related properties.

A team from the Wrocław University of Environmental and Life Sciences and Wroclaw Medical University (Associate Professor Helena Moreira, PhD, Associate Professor Ewa Barg, PhD, and Anna Szyjka, MSc Eng.) examined how different tea varieties affect the final characteristics of kombucha. Their findings revealed much larger differences than expected.

The researchers compared kombuchas made from black, green, white, oolong, and pu-erh teas. Their study was published in the journal Food Chemistry.

“The type of tea acts as a specific matrix that shapes the course of fermentation and the final composition of kombucha,” explains Associate Professor Helena Moreira, PhD, from the Department of Basic Medical Sciences and Immunology, Wroclaw Medical University. “Individual teas differ in their content of polyphenols, catechins, caffeine, and other bioactive compounds, which are subsequently metabolized by SCOBY microorganisms. As a result, fermentation proceeds with different dynamics, and the final beverages differ in both chemical and aromatic profiles.”

Kombucha is created when SCOBY, a symbiotic culture of bacteria and yeast, ferments sweetened tea. During fermentation, yeast converts sugars into alcohol and carbon dioxide, while bacteria transform those compounds into organic acids, primarily acetic and gluconic acids. These acids give kombucha its distinctive tart flavor.

Chemical Transformations Create Flavor and Aroma

Fermentation also changes many of the tea’s naturally occurring bioactive compounds. The researchers observed shifts in polyphenols, catechins, and volatile compounds that contribute to flavor and aroma.

“At the same time, transformations of polyphenols and volatile aromatic compounds present in tea take place. As a result, the beverage acquires its characteristic sour, lightly sparkling taste and a more complex aroma,” explains Associate Professor Helena Moreira, PhD.

The team found significantly higher levels of compounds associated with floral and fruity aromas, including linalool and 2-phenylethanol. These compounds are also found naturally in flowers and essential oils. Meanwhile, some substances typical of freshly brewed tea disappeared during fermentation and were replaced by new metabolites produced by the SCOBY culture.

Using advanced chromatography and mass spectrometry, the researchers tracked these changes throughout fermentation. The techniques enabled them to analyze and compare hundreds of compounds across kombuchas made from different tea varieties.

Different Teas Produce Distinct Kombucha Profiles

“The most surprising aspect was the scale of changes occurring during fermentation and how strongly they depended on the type of tea used,” says the scientist. “Despite identical fermentation conditions, we obtained kombuchas with highly distinct profiles of volatile aromatic compounds.”

The study also found notable differences in biological activity. Kombuchas made from green and oolong teas showed the strongest antioxidant activity and the greatest ability to neutralize free radicals.

Free radicals are highly reactive molecules that can damage cells and contribute to aging. Because of this, antioxidant compounds continue to attract significant scientific interest for their potential health effects.

“The results of our research indicate that the type of tea influences not only the taste and aroma but also the biological activity of kombucha,” emphasizes Associate Professor Helena Moreira, PhD. “Particularly interesting results were obtained for kombuchas prepared from green and oolong teas, which demonstrated the highest biological potential.”

Antioxidant Potential and Health Implications

Despite these encouraging laboratory results, the researchers caution that it is too early to draw firm conclusions about health benefits in people.

“Further clinical studies are necessary to clearly confirm the impact of particular types of kombucha on human health,” adds the researcher.

Interest in kombucha reflects a broader scientific focus on fermented foods. Fermentation can increase the availability of bioactive compounds, create new metabolites, and influence the gut microbiome.

“Fermented foods are currently at the center of scientific interest because they combine traditional technologies with a modern approach to health and nutrition,” says Associate Professor Helena Moreira, PhD. “Kombucha is a very good example of a product in which chemical composition, biological activity, and sensory profile result from complex interactions between the raw material and fermentative microorganisms.”

Why Every Kombucha Tastes Different

The findings highlight that kombucha is far from a uniform beverage. The type of tea used can produce major differences in both flavor and chemical composition.

Kombucha made from green tea developed a fresher, more vegetal aroma, while oolong tea produced stronger floral and fruity notes. Kombuchas made from black tea and pu-erh, by contrast, displayed richer, earthier aromas with more pronounced fermentation characteristics.

Reference: “Matrix-dependent modulation of chemical composition, volatile profile, and biological activity of kombucha beverages from different tea types” by Akshay K. Chandran, Marcelina Stach, Jacek Łyczko, Zbigniew Lazar, Joanna Kawa-Rygielska, Helena Moreira, Anna Szyjka, Ewa Barg and Joanna Kolniak-Ostek, 8 April 2026, Food Chemistry.
DOI: 10.1016/j.foodchem.2026.149160

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