Kombucha Side Effects 101

Kombucha touts many health benefits, but are there negative side effects of kombucha? And is it healthy for everyone to drink?

Kombucha has garnered a reputation as being a healthy powerhouse, with health benefits like gut-loving probiotics and antioxidants.

But are there any negative side effects of kombucha? And is it healthy for everyone? Let’s dig into the lesser loved potential side effects of kombucha so you can know if kombucha (and how much kombucha) is right for you.

Kombucha may cause Bloating and digestive discomfort

Anyone new to kombucha who’s guzzled down a bottle may have experienced this common kombucha side effect. There are a few reasons kombucha may cause bloating and digestive distress.

Probiotics: If you’re not used to consuming large quantities of probiotics, your gut may respond in rebellion at first. Introducing these new bacteria into your digestive system, while usually healthy in the long run, may upset your natural balance until your body gets used to regular kombucha consumption.

Carbonation: Kombucha is often carbonated (though you can drink it after the first fermentation), which can cause bloating for those not used to drinking carbonated beverages.

FODMAPs: Kombucha contains high levels of FODMAPs, which can cause digestive distress for some people. FODMAPs are sugars that are not completely absorbed in our intestines, and as result are the perfect “food” for the bacteria in our gut. The fermentation caused by the gut bacteria feeding on these FODMAPs can result in gas and bloating.

Kombucha may be Dangerous for some populations

Kombucha is an unpasteurized beverage consisting of many live bacteria and yeast cultures. While it should contain “good” bacteria, kombucha is brewed in an environment that can also be conducive to “bad” bacteria.

While a healthy immune system can handle unwanted kombucha bacteria without issue, certain populations should avoid kombucha. Further, kombucha contains trace amounts of alcohol and caffeine, and should therefore be avoided by some.

  • Immunocompromised people, such as those with autoimmune diseases, cancer, or kidney disease.
  • Young children, who’s immune systems may not be fully developed yet.
  • Pregnant and breastfeeding women, who may be more susceptible to infection, and who should avoid both alcohol and caffeine.

Caffeine and alcohol in kombucha can have side effects

Kombucha contains both caffeine and alcohol, which can have varying effects on people, depending on their sensitivities.

There are about 10 mg of caffeine per 8 ounces of kombucha. While this is less than the the 47 mg of caffeine in 8 ounces of black tea, it may still cause effects in people who are sensitive to caffeine. Effects include jitters, nausea, nervousness, and digestive distress. Also be aware of caffeine content when drinking kombucha in the evening.

Kombucha also contains trace amounts of alcohol, though homemade kombucha may contain higher amounts than store bought kombucha. Keep this in mind if you suffer from alcohol addiction. (This tool measures alcohol content of homemade kombucha if you want to track the levels of your brew!)

COntaminated kombucha can be dangerous

If your kombucha becomes contaminated with fungus, mold, or bad strains of bacteria, it can be dangerous to consume (regardless of how healthy your immune system is). Contaminated kombucha can cause stomach upset, allergic reactions, nausea, head and neck pain, and even death. (See our guide to mold in kombucha here!)

To avoid contamination, ensure you are using good quality, fermentation-safe supplies. For instance, kombucha should always be brewed in glass or ceramic containers. Plastic containers are porous and may harbor bacteria, while metal containers can be reactive and lead to metal toxicities.

You must also be sure to keep your fermentation supplies and process as clean as possible. Sterilize all tools and containers regularly with boiling water and vinegar.

And of course, use common sense! Throw away the entire batch if you find mold, and be aware of any taste changes in your brew.

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18 thoughts on “Kombucha Side Effects 101”

  1. Need advice. First brew was great. Used cut up fruit for f2. But struggled to get out fruit pieces after poured out. Second brew decided to grind up fruit, but it doesn’t look great. Wondering what is best for f2?

  2. Thanks for your very helpful site. I am just making my first scoby and look forward to tasting my own kombucha.
    If I am using a hydrometer to test for alcohol content, what reading would indicate a low alcohol level?

  3. I drank one sip of some store bought and my face became itchy and spotted. Later my arm did as well. I thought I was having an allergic reaction. The flavor I drank has hibiscus in it so I was worried may be I was allergic to that. I’m not sure. Should I try again with little bits every day to see if I’m allergic or if it’s part of getting all the toxins out of my body?

  4. Hi, my daughter drank about a cup of store bought kombucha out of the bottle but I think it had been opened at least a week previously. Is this safe? I couldn’t taste it to test myself as she drank the last amount in there. It has been refrigerated. Thank you!

    • Hi Lizzie! She should be fine – kombucha doesn’t really go bad do to the acidity and live nature of it (especially if it’s been in the fridge).

  5. Another “side effect” that I and others have experienced is that the culture in kombucha can produce histamines which cause an allergy-like reaction. If I drink kombucha after not having any for a long time, I’ll get itchy all over, but it goes away after consuming kombucha again for a while.

  6. Hi i like the glass jar with the tap, but the one I found seemed to have a plastic fitting inside hard so I returned it. I thought it is sci d is and should only touch glass.is yours hav ed that fittin.
    Thankyou Cyndi

    • Hi Cyndi! Mine actually does have that plastic fitting and I haven’t had a problem. If the plastic is fermentation grade it should be fine (as long as you keep an eye on it and clean it regularly).

  7. Okay… I have asked about alcohol and amount on your mold page. sorry about that, I got all the answers on this one. Thanks!!

    • Hi for 2 weeks I have been drinking captain gutsy kombucha, but I am suffering severe bloating and gas and stomach and side pain. I suffer from IBS so I am assuming this is what’s causing it? I am very frustrated as I really want to have the good bacteria