Kombucha Side Effects: 7 Real Risks, From Bloating to Acidity

Some links here are affiliate links. If you buy through them we may earn a small commission at no extra cost to you. We only point to products we would suggest to our own family.

Kombucha Side Effects: The Short Answer

Kombucha side effects are real, even though kombucha is sold as a health drink. Some people also search for it as kambuja or kombucha tea.

It is a fermented tea made with tea, sugar and a SCOBY, a mix of bacteria and yeast. As it ferments, the sugar turns into acids, gas and a little alcohol.

That alcohol is the fact most people miss. The US Alcohol and Tobacco Tax and Trade Bureau (TTB) says fermentation "may produce a kombucha with an alcohol content of 0.5% or more alcohol by volume."

In India, the FSSAI alcoholic beverage rules call a drink with "more than 0.5 per cent. abv" an alcoholic beverage. So that 0.5% line matters here too.

None of this means kombucha is bad for everyone. For the other side, read what kombucha actually does for your body.

1) Bloating and Gas

This is the side effect people notice first. You may feel full, burp a lot or get cramps after one glass.

The fizz is the main reason. The US health agency NIDDK says you swallow more air when you "drink carbonated, or fizzy, drinks."

It also says eating or drinking too fast adds more air. So gulping a cold bottle is the worst way to try it.

What helps:

• Start with a small glass, not a full bottle.
• Sip slowly, and drink it with food.
• If other fizzy drinks bloat you, expect kombucha to do the same.
• Stop if the bloating comes back every time.

2) Acidity and Acid Reflux

Many people ask, "Is kombucha good for acidity?" We found no good proof that it helps.

The drink itself is very acidic. A 2025 review in Foods says the pH of finished kombucha "can range from 2.5 to 3.5."

NIDDK says foods and drinks "commonly linked to GERD symptoms include acidic foods" and "coffee and other sources of caffeine." Kombucha is acidic, and Cleveland Clinic notes "the little bit of caffeine found in kombucha."

So if you get heartburn, sour burps or chest burning, kombucha may add to it. The NHS also advises not to eat "within 3 or 4 hours before bed" if you have reflux.

• Skip kombucha on an empty stomach.
• Do not drink it late at night.
• Avoid it with oily or very spicy meals if those trigger you.

For drinks that are gentler on the stomach, see which juice is good for gastric and acidity.

3) Stomach Upset, Nausea and Loose Stools

Some people get nausea, stomach pain or loose stools after kombucha. Others feel fine.

Cleveland Clinic says drinking too much "could potentially lead to reactions like headache, nausea, GI distress." The US military's health resource, HPRC, lists "stomach problems, nausea, vomiting" when kombucha is brewed incorrectly.

We found no good study on kombucha and loose stools alone. So treat it as one form of stomach upset, not a proven effect.

Have IBS or another gut problem? Talk to your doctor before you add any fermented drink.

Add only one new food at a time, so you can tell what is causing trouble.

See a doctor if you get blood in your stool, high fever, or pain that will not go away.

4) Headache When You Drink Too Much

Headache is one of the reactions Cleveland Clinic links to drinking too much kombucha.

The same source mentions a rare but serious risk: ketoacidosis, which it calls "a medical emergency where there's too much acid in your blood."

Sugar is another thing to watch. Cleveland Clinic says some kombuchas are more sweetened than others, and that "4 grams of added sugar equals 1 teaspoon of sugar."

So read the label before you drink a whole bottle. Our guide to kombucha benefits covers what the drink can and cannot do.

5) Trace Alcohol

Cleveland Clinic says "Alcohol levels are typically below 0.5%" in regular kombucha. That is why it can be sold as non-alcoholic.

But a 2023 review in Foods says alcohol "can be produced in kombucha at levels ranging from 0.7-1.3%" during fermentation. The longer it ferments, and the warmer it gets, the harder it is to know.

This matters if you avoid alcohol for health, religious or family reasons. It also matters in pregnancy and for children.

The TTB says "fermentation may continue in the bottle after it leaves the production facility." So the alcohol can rise after you buy it.

Keep bottles cold and drink them before the date on the label. For the full story, read is kombucha alcoholic?

6) Tooth Enamel Wear

Kombucha is acidic, and there is a number for it. A 2025 review in Foods reports a pH of 2.5 to 3.5 for finished kombucha.

The American Dental Association says "Frequent consumption of soft drinks, particularly carbonated sodas, is a primary risk factor for erosive tooth wear." Kombucha is both fizzy and acidic.

The UK's Oral Health Foundation gives simple tips:

• "Limit acidic foods and drinks to mealtimes."
• "Use a straw to reduce contact with the teeth."
• "Wait at least one hour after eating or drinking before brushing your teeth."

The ADA also suggests you "rinse the mouth with water after consuming acidic drinks." Do not swish kombucha around your mouth.

7) Contamination in Homemade Kombucha

Homemade kombucha is fun to make, but it is easy to get wrong. Memorial Sloan Kettering says "Allergic reactions, jaundice, serious illness, and death have been associated following consumption of home-grown kombucha tea."

Serious cases are rare, but they do happen. A 2025 review in Current Nutrition Reports tells of one woman who had nausea and vomiting after homemade kombucha.

She died, and lactic acidosis was found in her blood tests. That is a single case report, not a common outcome, but the review stresses "meticulous preparation in the production stages."

The pot matters. Because kombucha is so acidic, it can pull lead out of some glazes.

Poison Control says "Lead poisoning occurred after kombucha tea, which is acidic, was brewed in ceramic containers." Cleveland Clinic warns about clay vessels too.

Canada's BC Centre for Disease Control says "Ferments must be done in glass or other approved food containers that are not reactive to high acid environments."

• Do not brew in a matka, clay pot or glazed ceramic jar.
• Wash jars and tools well before every batch.
• Throw out any batch with fuzzy mould or a rotten smell. Do not taste it.

Not sure if it is mould? See kombucha mold vs kahm yeast. Warm Indian summers also speed things up, as we explain in kombucha in summer.

How Much Kombucha Is Safe per Day?

Cleveland Clinic says the CDC advises that about 4 ounces of kombucha per day "may not cause adverse effects in healthy persons." That is about 120 ml, one small glass.

It also notes that "most kombucha bottles sold at the store are more than 4 oz." HPRC says serving sizes range "anywhere from 8-20 ounces."

So drinking kombucha every day is not the main problem. Drinking a big bottle every day is more likely to cause side effects.

Who Should Avoid Kombucha?

• Pregnancy and breastfeeding. A 2023 review in Foods says kombucha is "contraindicated in special populations, including pregnant women, infants, and children under the age of 4." It adds that alcohol can harm "pregnant and lactating women as well as young children."
• Young children. BCCDC suggests labels say it is "Not a suitable beverage for young children or during pregnancy."
• Weak immune system. Cleveland Clinic says if you are pregnant "or have a compromised immune system, it's probably best to find another drink of choice."
• Long-term illness. HPRC says "those with chronic conditions should avoid drinking kombucha until more reliable information is available."

Pregnant? Read our full guide on kombucha during pregnancy.

Kombucha Side Effects at a Glance

How to Drink Kombucha More Safely

• Start with a few sips, then a small glass.
• Pick a sealed, chilled bottle, and check the sugar on the label.
• Do not drink it during a stomach flare.
• Keep it away from young children.
• Stop if you get bloating, reflux, rash or headache again and again.

If you brew at home, check the pH. BCCDC says the "Recommended pH is between 2.5 and 4.2." Cheap paper strips give a rough reading.

The LABART pH indicator paper has 200 strips with a pH 1 to 14 range (Rs 349 on Amazon.in, 20 October 2026). The Kombucha pH test strips cover a narrower 0 to 6 range, with 100 strips (Rs 550).

A pH strip only checks acidity. It cannot spot mould or germs, so use your eyes and nose too.

Check pH Strips on Amazon

Store and serve in glass. We make a 5 litre borosilicate glass dispenser with a steel tap. Its product page says the steel tap will not corrode with acidic drinks.

It is a serving and storage jar, not a fermenting kit. We sell it, so weigh that when you read this tip.

InstaCuppa Glass Water Dispenser 5 Litre

Shop Now

🔥 InstaCuppa Best Sellers

InstaCuppa Portable Blender for Smoothie and Juices, Milk ShShop NowInstaCuppa Premium Electric Chopper with 3 Unique AttachmentShop NowInstaCuppa Portable Blender with 4000 mAh Rechargeable BatteShop NowInstaCuppa Multipurpose Electric Kettle Cum Cooker with FreeShop NowInstaCuppa Insulated Water Bottle 1L — Stainless Steel ThermShop NowInstaCuppa Milk Frother for Coffee - Handheld Battery-OperatShop NowInstaCuppa Rechargeable Mini Electric Chopper, Chops In LessShop NowInstaCuppa Portable Multi Cook Electric Kettle with Non-SticShop NowInstaCuppa Automatic Curd Maker Machine | Probiotic-Rich YogShop NowInstaCuppa Automatic Water Dispenser for 20 Liter Cans with Shop NowInstaCuppa Portable Blender for Smoothie and Juices, Milk ShShop NowInstaCuppa Premium Electric Chopper with 3 Unique AttachmentShop NowInstaCuppa Portable Blender with 4000 mAh Rechargeable BatteShop NowInstaCuppa Multipurpose Electric Kettle Cum Cooker with FreeShop NowInstaCuppa Insulated Water Bottle 1L — Stainless Steel ThermShop NowInstaCuppa Milk Frother for Coffee - Handheld Battery-OperatShop NowInstaCuppa Rechargeable Mini Electric Chopper, Chops In LessShop NowInstaCuppa Portable Multi Cook Electric Kettle with Non-SticShop NowInstaCuppa Automatic Curd Maker Machine | Probiotic-Rich YogShop NowInstaCuppa Automatic Water Dispenser for 20 Liter Cans with Shop Now

Some links here are affiliate links. If you buy through them we may earn a small commission at no extra cost to you. We only point to products we would suggest to our own family.