Kombucha: It’s Trendy, but Is It Safe?

Medically Reviewed by Brunilda Nazario, MD on January 25, 2016

Jan. 25, 2016 -- Many of us opt for a jolt of java to wake our brains up in the morning or midday, but some say a mug of "mushroom tea" might be a better choice.

Kombucha tea is being touted as good for your health. But is it really, and is it safe?

The trendy product is creating quite a stir these days as headlines and the U.S. government warn it may give you a buzz instead of a mental boost.

Last fall, the U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB) told several kombucha makers their fermented tea products contained too much alcohol and they might have to pay up if they didn't label or reformulate the goods. The action continues to spark much debate over the safety of the popular tea.


Kombucha is a centuries-old concoction that's made by mixing (or fermenting) black, green, or oolong tea and refined sugar with bacteria and yeast. The slightly sweet, slightly sour, bubbly beverage contains B vitamins and probiotics (aka helpful bacteria) -- all of which can be good for our bodies and brains.

And consumers are gobbling it up. A 2015 Markets and Markets analysis calls kombucha "the fastest-growing market in the functional beverages category." It projects sales of the drink to soar to $1.8 billion by 2020.

A Brain Booster or Bust?

The scientific evidence to support the health benefits of kombucha itself is limited. But studies continue to show its nutrients are likely a healthy choice.

"Probiotics, or the good gut bacteria, are being linked to multiple health benefits, including improved digestion, immune health, fighting depression, and even improved dental health in children," says dietitian Heather Mangieri, spokeswoman for The Academy of Nutrition and Dietetics.

One recent study says fermented foods like kombucha may be particularly good for brain development and behavior. Its beneficial bacteria and B vitamin content help place it on the smart "brain food" list.

Michelle Crowder, ND, senior naturopath at Beaumont Hospital in Grosse Pointe, MI, calls the connection between fermented foods and mental health “a very active and exciting area of research.”

"We do know from a biomedical standpoint that B vitamins are ... important for nervous system function and hormone and [nerve signaling] balance," Crowder says. While kombucha may have some or all of the health benefits of tea, she adds there is marketing behind the beverages.

“Some of the health claims are likely overstated, but it does seem that true health benefits do exist.”

Brian Nummer, PhD, Utah State University Extension food safety specialist, authored a special report on kombucha in the November 2013 Journal of Environment Science. He says: "There is likely no harm in ... considering kombucha healthy. I would just caution people from elevating it to a panacea."

Can Kombucha Get You Drunk?

The live cultures that are purported to make kombucha healthy play a key role in its possible alcohol content. Kombucha makers call the live culture mix "SCOBY," short for "symbiotic culture of bacteria and yeast." It forms a mushroom-like film on top of the beverage during the typical 7-10 day fermentation process. (Thus its friendly name "mushroom tea.") During that time, the bacteria and yeast gobble up the sugar in the tea, producing vitamins, acids, and traces of ethanol alcohol. Alcohol is a natural by-product of fermentation.

"Many fermented foods and even ripe fruit and fruit juice contain trace amounts of alcohol due to the same process," Nummer says. "If prepared, stored, and consumed correctly, the amount of alcohol in the finished kombucha product should be minimal, less than 0.5%." (Under federal law, products over 0.5% alcohol by volume must be regulated and marketed as an alcoholic beverage.)

That's an important phrase: properly stored. After kombucha is made, the product must be kept cold to prevent further fermentation. If not, the alcohol level can rise. But a spoiled kombucha likely won't taste very good, and it's probably not going to get you drunk either.

"These reports [that you can get drunk from kombucha drinks] are grossly overstated," says Michelle Schoffro Cook, PhD, DNM, author of The Probiotic Promise. "The likelihood of getting more than a minute amount of alcohol is highly unlikely. You're more likely to get alcohol in ... vinegar."

Many others agree, including all those interviewed in this article and at least one member of Congress. In reaction to the TTB's warning letters, Boulder, CO, Democratic Rep. Jared Polis penned a letter to the government agency asking them to back off and reconsider their "out-of-date testing" methods.

How Much Kombucha Is Safe?

Some experts advise against drinking kombucha tea, citing reports of side effects including stomach problems and allergic reactions and a lack of research into its effects.

Others advise moderation. The CDC, for instance, recommends that you not drink more than 4 ounces of kombucha a day. The agency’s warning came after two women who drank bad bottles of kombucha in very high amounts (12 ounces a day) became very sick. One of them, a 59-year-old, died. Both women drank tea originating from the same colony of yeast and bacteria. But the CDC did not formally link the death to the drink.

"Like most things, more is not better," Mangieri says. "As a precaution, young children, pregnant women, and anyone with a compromised immune system should avoid drinking kombucha tea until further evidence is available."

Kombucha is available at health food stores and grocery stores. Or you can buy a starter kit and make it at home. If you do, be sure to follow proper homebrewing and food-safety guidelines to prevent food-borne illness. Keep your work area and materials very clean to reduce contamination, and toss out anything that looks suspicious or smells unpleasant.

When shopping for kombucha, always check the labels. Cook suggests you choose one that has less than 5 grams of sugar per serving to reduce the chances of it containing any alcohol. Keep in mind that some kombuchas are made to contain more alcohol, and they are (or should be) labeled and sold as such.

Remember that there is no single food of beverage that is going to save your health. You have plenty of options for a healthy diet.

Mangieri admits she doesn't like kombucha. "But if you don’t, there are plenty of other ways to get probiotics into your diet. For example, yogurt, kefir, aged cheeses, kimchi, pickles, tempeh, and sauerkraut, just to name a few."

Show Sources


Heather Mangieri, MS, RDN, CSSD, spokeswoman, The Academy of Nutrition and Dietetics; owner, Nutrition CheckUp, LLC. 

Brian A. Nummer, PhD, Utah State University Extension food safety specialist. 

Nummer, B. Journal of Environmental Health, November 2013. 

Michelle Schoffro Cook, PhD, DNM, author, The Probiotic Promise

Michelle Crowder, ND, senior naturopath, Beaumont Hospital, Grosse Pointe, MI. 

U.S. Alcohol and Tobacco Tax and Trade Bureau: "Kombucha," "TTB Publishes New Kombucha Page, Including New Frequently Asked Questions (FAQs)." 

CDC: "Unexplained Severe Illness Possibly Associated with Consumption of Kombucha Tea." 

Nguyen, K. SpringerPlus, Feb. 24, 2015. 

Vīna, I. Journal of Medicinal Food, Feb. 18, 2014. "Food Freedom: Polis Pushes Feds to Lay Off Kombucha Firms." 

Dash, S. Current Opinion in Psychiatry, January 2015. 

News release, Markets and Markets.

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