Kombucha has become one of the world’s most popular fermented drinks, often praised for its tangy flavor and possible health benefits.
But new research suggests that the type of tea used to make kombucha can dramatically change not only its taste and aroma, but also its chemical composition and biological properties.
Researchers from the Wrocław University of Environmental and Life Sciences and Wroclaw Medical University compared kombucha made from five different teas: black, green, white, oolong, and pu-erh.
Their findings, published in Food Chemistry, showed that each tea created a surprisingly different final beverage, even when all fermentation conditions were kept the same.
Kombucha is made by fermenting sweetened tea with a SCOBY, a symbiotic culture of bacteria and yeast.
During fermentation, the microorganisms break down sugar into alcohol, carbon dioxide, and organic acids such as acetic acid, which gives kombucha its sour taste.
At the same time, many of the natural compounds already present in tea also change. These include polyphenols, catechins, caffeine, and aromatic molecules that influence flavor and potential health effects.
According to Helena Moreira, the tea itself acts like a “matrix” that shapes how fermentation unfolds and determines the final characteristics of the drink.
Using advanced chemical analysis techniques, the researchers tracked hundreds of compounds during fermentation. They found that some substances commonly present in fresh tea disappeared, while entirely new compounds were produced by the SCOBY microorganisms.
Fermentation also increased compounds associated with fruity and floral aromas, including linalool and 2-phenylethanol, which are also found naturally in flowers and essential oils.
One of the biggest surprises was how differently each tea behaved.
Green tea kombucha developed a fresher, more plant-like aroma, while oolong tea produced stronger fruity and floral notes. Black tea and pu-erh kombuchas developed heavier, earthier, and more fermented flavors.
The differences extended beyond taste and smell.
The researchers also measured antioxidant activity, which reflects how well substances can neutralize harmful molecules known as free radicals. Free radicals can damage cells and are linked to aging and various diseases, so antioxidants are often studied for their possible health benefits.
Among all the tested beverages, kombuchas made from green tea and oolong tea showed the strongest antioxidant activity and the highest ability to neutralize free radicals.
The researchers emphasize that these findings do not prove specific health benefits in humans yet. More clinical studies are needed before scientists can confirm exactly how different types of kombucha may affect health.
Still, the study highlights how fermentation can significantly transform foods and beverages. Scientists are increasingly interested in fermented products because fermentation can improve the availability of beneficial compounds, create entirely new molecules, and potentially influence gut health.
The researchers say kombucha should not be viewed as a single uniform product. Instead, its chemistry, flavor, and possible biological properties depend heavily on the type of tea used from the very beginning.
In other words, choosing a tea for kombucha is not just about taste—it may shape the drink’s entire character.
