Your Kombucha May Have More Alcohol in It Than You Assume (Especially if It’s Homemade)

America’s favorite fermented tea drink has reached peak popularity.

Remember when kombucha was only available to those who brewed it at home? Needless to say, those days are long over. A now billion dollar industry, kombucha can be easily found at grocery stores, health food retailers, and even most gas station marts and bodegas. While the health benefits associated with this fizzy beverage have piqued consumer interest, there are still a few question marks when it comes to kombucha…including interesting (murky?) claims related to its trace alcohol content. Let’s take a closer look.

Health benefits of kombucha

First things first: For those who haven’t tried it, kombucha is tea that’s created by process of fermentation. In this case, fermentation is occurring when bacteria, yeast, and other microorganisms interact with tea and sugar, yielding tangy flavor and potent probiotic potential that many people love. Typically, these gut-promoting organisms are introduced through something called a SCOBY, or symbiotic culture of bacteria and yeast.

The health benefits that result from this tasty science experiment are certainly noteworthy. Kombucha is a good source of probiotics, or healthy bacteria, that can help boost the population of helpful bacteria in our gut microbiome. Beyond promoting healthy digestion and metabolism, a healthy gut microbiome is linked to many other positive health outcomes, from a stronger immune system to better brain and mental health.

Kombucha also provides a healthy dose of B vitamins including folate, niacin, B6, B12, thiamin, and riboflavin—all of which are vital for maintaining your body’s energy levels and metabolism. And thanks to the tea it contains, kombucha is full of plant compounds as well, especially EGCG (epigallocatechin gallate), kaempferol, and quercetin. These compounds have powerful antioxidant and anti-inflammatory properties. Finally, kombucha is high in organic acids like acetic acid, a potent antimicrobial agent that has also been linked to improved blood pressure regulation.

What to know about kombucha and alcohol

Glossy potential gut benefits aside, there are a few things to keep in mind when drinking kombucha…especially if you do so daily. While some kombucha brands certainly do contain more than a minimal amount of added sugar and/or caffeine (be sure to read labels if those are things you’re not interested in guzzling), one of the bigger debates surrounding kombucha is the alcohol it contains. Read: The fermentation process involved in creating kombucha will always yield some alcohol. But to legally be sold in grocery stores, the Alcohol and Tobacco Tax and Trade Bureau (TTB) mandates that every bottle of kombucha must have less than 0.5 percent alcohol by volume (ABV) to be sold as a non-alcoholic beverage.

Surprisingly, on their website, the TTB directly addresses the potential for kombucha’s alcohol content to increase as it’s sitting in the bottle, continuing to ferment. Here’s where things get interesting. In 2010, there was a widespread kombucha recall because the Food and Drug Administration (FDA) was finding alcohol content to be anywhere between 0.5 and 2.5 percent ABV. Fast forward 10 years, and a 2020 study done by the British Columbia Centre for Disease Control found that, after testing nearly 700 samples of kombucha (from brands many of us know and love), the alcohol content of 32 percent of bottles off grocery store shelves was actually measuring anywhere between one and in excess of three percent ABV. Considering a beer can have as little as four percent ABV, this is obviously a concern.

A 2020 study done by the British Columbia Centre for Disease Control found that, after testing nearly 700 samples of kombucha (from brands many of us know and love), the alcohol content of 32 percent of bottles off grocery store shelves was actually measuring anywhere between one and in excess of three percent ABV. Considering a beer can have as little as four percent ABV, this is obviously a concern.

But when you’re homebrewing ‘booch, it’s much easier to accidentally brew something closer to a hard cider than a fermented tea drink. Taking a small dive into the science here, when kombucha is made, alcohol is produced by the action of the yeasts in the mix and is then broken down by the bacteria introduced by the SCOBY to keep it from becoming a full-blown alcoholic beverage. So, if you have an imbalance here—namely an overpopulation of yeast and an under-population of bacteria—you’re going to end up with much more ethanol (aka alcohol) in your kombucha than you may have been intending.

This can also be exacerbated by brewing, storing, or transporting this fermented tea at higher temperatures (over ~73 degrees Fahrenheit) as it promotes yeast activity. This may very well be the root cause for bottles of kombucha in grocery stores having higher alcohol content than they claim.

Unaccounted-for yeast also exists naturally in the air, which can impact your process of making kombucha at home. Here are some ways to try to manage yeast populations at home:

• Avoid taking starter tea from your old kombucha brew at the bottom of the jar, as this is where yeast is most concentrated
• Limit how much sugar and fruit you add to the brew, as this is what the yeast feeds on
• Ferment for fewer days, reducing the amount of alcohol that can be produced
• Increase the bacteria in your brew through using a larger SCOBY
• Make sure the brew has exposure to air to keep those bacteria thriving

All of the above being said, more often than not, the kombucha you buy from the grocery will have the alcohol content mandated by TTB. However, there is still plenty of evidence suggesting that if you’re a frequent buyer, some of those bottles just might have a higher ABV.

This may not be a major concern if you drink the fizzy stuff infrequently, at home relaxing, or during some other time of leisure. But if you are sensitive to alcohol, have health concerns that alcohol exacerbates, or are pregnant, you may want to be cautious of how much kombucha you’re consuming. And always make sure you keep your ‘booch cold!