Kombucha is a fermented drink made from sweetened black or green tea. It is produced by fermenting tea with a symbiotic culture of bacteria and yeast (Scoby). The fermentation process gives kombucha its characteristic light fizz and tart flavor. It can also be enhanced with fruit juice or spices.
The fermentation process of kombucha involves several steps:
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Black or green tea leaves are steeped in hot water – then sugar is added.
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The mixture is mixed with bacteria and yeast and left to ferment at room temperature for 1-2 weeks.
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During fermentation, bacteria and yeast form a cellulose layer on the surface.
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The resulting fermented liquid is the kombucha tea that we drink.
What are the health benefits of kombucha?
Kombucha contains a range of potentially health-promoting compounds produced during fermentation, including the following.
organic acids
Antimicrobial: The organic acids found in kombucha may have antimicrobial properties that may help you sleep.
Detoxification: Some may also help cleanse your liver.
Antioxidant: Powerful antioxidants (polyphenols) may protect against various diseases – for example, heart disease. Green tea kombucha contains more antioxidants than black tea.
Vitamins and Electrolytes
Kombucha also contains vitamin B, which is linked to healthy aging, mood, memory and reducing the chance of stroke or obesity. It contains some vitamin C – another antioxidant – which may help reduce stress hormones (cortisol).
probiotics
Kombucha is a fermented tea which means it’s full of friendly microbes that feed the good bacteria in your gut. These good bacteria improve gut health, boost immunity and regulate nutrient absorption and bodily functions.
Fitness and nutrition consultant Dr. Chris Mohr, a former sports nutritionist for the American football team the Cincinnati Bengals and the University of Massachusetts athletic program, says kombucha may provide similar benefits to other fermented foods – like improving digestion and boosting immunity.
She adds, “The probiotics found in kombucha may help maintain a healthy gut, which is good for people with conditions like irritable bowel syndrome (IBS).” “The antioxidants in kombucha may also help with liver health.”
However, Mohr cautions that kombucha should not be used as a treatment for specific medical conditions.
“Although some kombucha drinks contain ingredients with potential benefits, the actual health effects – and the amounts required – require more scientific research to confirm these claims,” he notes. “The probiotic content of kombucha can also vary – depending on the fermentation process.
“Alternative fermented foods, such as plain yogurt – especially varieties labeled with ‘live and active cultures’ – are a more reliable source of probiotics.”
Kombucha contains caffeine – but in much smaller amounts than coffee or tea.
ABIM quadruple board-certified physician Dr. Raj Dasgupta says kombucha contains some caffeine because it is made from tea – which naturally contains caffeine.
“The exact amount can vary depending on the type of tea used and how it is made,” he explains. “If you’re watching your caffeine intake, it’s worth checking the label or asking about the tea base when choosing kombucha.”
Kombucha produces small amounts of alcohol during fermentation – usually less than 0.5%. The longer kombucha is fermented, the higher the alcohol content. Dasgupta explains that store-bought versions are generally safe, although there may be a slight chance of containing harmful bacteria if it is not prepared or stored properly. Buy kombucha only from trusted sources.
Research into the potential health benefits of kombucha continues. The acids present in kombucha may help the growth of friendly gut bacteria. But contamination during fermentation can cause additional health conditions like an imbalance of acids in your body (metabolic acidosis). The high acidic levels of kombucha can also damage your tooth enamel, leading to tooth decay.
Mohr advises: “Moderation is key when it comes to kombucha — especially if you’re new to drinking it. Start with smaller doses to reduce the chance of harmful effects like bloating or digestive problems.”
Dasgupta says that — for most people — drinking up to one can of kombucha a day is generally considered safe. However, tolerance may vary from person to person.
Michelle Rothenstein, MD, heart disease management and prevention expert at Well-Nourished, says people with weakened immune systems or sensitivity to caffeine should use caution when consuming kombucha.
You shouldn’t drink kombucha if you’re pregnant because the acid, alcohol, and caffeine content — along with the fact that it’s unpasteurized — could harm your baby. Those ingredients mean children shouldn’t drink kombucha either.
The sudden rise in popularity of kombucha may also lead to safety issues. Poor quality ingredients, improper containers, and unhealthy fermentation create the potential for toxin contamination. To ensure safety and quality, health organizations must set legal guidelines for production methods, materials, and quality control.
Dasgupta cautions that if you’re pregnant or breastfeeding, have a compromised immune system, or suffer from severe acid reflux, stomach ulcers, or alcohol sensitivity, it’s a good idea to talk to your doctor before trying kombucha.
“Its fermentation process and ingredients may pose a risk to these people,” he explains.
He adds that kombucha may also interact with some medications. This is due to the presence of certain by-products formed during the fermentation process. These by-products can affect the way the medicine is absorbed or metabolized in your body.
Mohr says: “If you’re taking any medications — especially for diabetes, liver or kidney problems — it’s best to avoid drinking kombucha.”
While it is safe to drink in moderate amounts, the health benefits of kombucha lack strong scientific support. Enjoy it as a refreshing drink, but don’t expect it to fix everything. Check labels for caffeine and alcohol content and remember, more research is needed to confirm its health claims.
