Is Kombucha Safe?

Recently I met a woman who brews kombucha, and I couldn’t help but ask if she had an extra scoby (symbiotic culture of bacteria and yeast) so I could try my hand at fermenting it myself.


A kombucha scoby is a flat, rubbery disc that floats in a sweetened tea medium. There are a number of organisms in the mix, but for simplicity’s sake, we’ll say that there are two classes of critter involved, various yeast species, which ferment the sugars into alcohol, and various vinegar-forming bacteria, which ferment the alcohol into several organic acids, giving the finished drink an apple cider vinegar pucker and a bunch of interesting components that the average American diet likely doesn’t provide.

Some people praise kombucha as a miracle elixir that cures everything from baldness to arthritis to cancer; others insist it is untested and dangerous.

Look, kombucha had me at “fermented by a scoby.” I just can’t pass up what I’m calling a Microbial Village. That said, I want to understand what risks there are so I can minimize them procedurally, or make an informed decision about whether kombucha is safe to drink.

As far as I can tell, the CDC has documented a total of three (3) hospitalizations linked to kombucha – two in Iowa in 1995, where one woman died, and one in 2009. All three were suffering acidosis, in which the body can no longer regulate its pH and the blood becomes acidic.

Those are real data points, and certainly many more people may have had less serious negative reactions that didn’t require medical attention.

That sounds like a pretty tough indictment of kombucha right there, until you consider that caffeine sends thousands of people to the hospital every year, and has been linked in a handful of deaths, especially from products where caffeine is mixed with other stimulants and can create synergistic effects in the body. Admittedly, caffeine is used daily by the vast majority of the population of the US, but still. You’d think that if kombucha were some sort of silent killer, there would be more than three documented cases of serious injury in 18 years.

And then there’s alcohol, which is really the point of this whole blog. It’s a lot of things, but I can say with clear conviction that I don’t drink for my health. How many hospitalizations result from alcohol on an average Saturday night?

So is kombucha safe? Store bought, I’m going to say yes, in that the product will almost certainly be free of contamination. Will your body love a sudden infusion of live culture enzymes and organic acids? That I can’t tell you. Will it impact how your body uses prescription drugs you may take? I can’t tell you that either. I have a friend who hasn’t eaten grapefruit in years because it was preventing proper absorption of certain of his prescription drugs.

What about home brewed kombucha? Is that safe? That’s a more qualified yes – kombucha can’t be airlocked as it ferments because it needs to breathe, and the home brewer is pouring in cooled, heavily sweetened tea that needs some time to develop a pH adequate to ward off pathogens.

So there’s a risk of contamination, and it’s higher than in most contemporary home brewing scenarios. Interestingly, the scoby usually floats at the surface and will grow to the width of its container, so a mature colony acts a little bit like an oxygen barrier, keeping the fermentable liquid submerged (though this is hardly a perfect seal).

And come on, in nature, a sugary solution will usually become alcohol, and an alcohol solution will usually become vinegar. These are not unique processes. These are the normal pathways of sugar decomposition, seen everywhere that fruits ripen or honeycomb becomes damp.

So, I’m having a good time playing with my new kitchen pet and enjoying the tasty drink it produces. I thoroughly wash my hands before interacting with it, and I monitor it carefully for off odors or signs of surface mold. I’m starting additional scobys as a fallback in case mold or other problems develop, and I was inspired to pour some very old live vinegar dregs into a jar with some bad wine to see if I can’t make a vinegar mother, a very similar complex, producing a similar product.

My kitchen may never be the same!

For another take, here’s a good piece from other experienced fermenters who’ve decided to steer clear of kombucha.

We Support Georgia HB 314 / SB 174

There are a lot of changes brewing on the legal front here in the south. Alabama is looking to legalize homebrewing once and for all, while here in Georgia, legislators may roll back one more of the state’s blue laws and allow breweries and brew pubs to sell direct to consumers for off-site consumption.

Yep, you read that right. As the law stands today, if you take a brewery tour at Terrapin, Red Brick, Monday Night, or any of Georgia’s other craft breweries, you can sample beer as part of the tour, but you can’t buy a six pack of your favorite to take home. And if you have a great meal and a great beer at a brewpub like 5 Seasons, Twain’s, or The Wrecking Bar, you can’t buy a growler of their brew to take with you and have with dinner.

It’s a ridiculous prohibition that other states don’t force their businesses to live under, and it needlessly and unfairly penalizes breweries in a way that the vineyards of North Georgia aren’t forced to endure.

This blog proudly joins the Georgia Craft Breweries Guild, John Cochran of Terrapin Beer, Twains, 5 Seasons, and the rest of Georgia’s vibrant and growing craft beer community in supporting passage of HB 314 / SB 174.

If you would like to see one more senseless law rolled back and craft brewers empowered to sell their product more widely, please contact your state House and Senate representatives to let them know you support Georgia’s small business owners and craft beer culture.

Anatomy of a Nelson Sauvin-Calypso Belgian IPA

For months, I shared my home with the most beautiful carboy I’ve ever created, a work of art in red. Hop’s End Belgian IPA was meant to be an experience of the fruitier-grapier end of the hops spectrum, featuring Nelson Sauvin, Calypso, and a touch of Cascade and “Magic Hop Dust” from Austin Homebrew Supply for backbone (full recipe here).

Even the cat thought it was stunning.

Even the cat thought it was stunning.

It went through a true secondary and an additional racking into tertiary, where it dry hopped on yet more Nelson Sauvin, and there it sat for the winter.

Unfortunately, on bottling day, a heavy sulphury aroma greeted us. I’d noticed it in earlier manipulations, but kept hoping it would dissipate. It seems to be DMS, dimethylsulfate, which can hang around if you don’t have a rolling boil happening during the brewing (though I’ve never experienced it before). Fortunately, it seems to be dissipating as the beer bottle conditions, though unevenly.

On bottling day, thus the lack of carbonation.

On bottling day, thus the lack of carbonation.

At its best, this beer has a wonderful, clean bite, with a rounded fruityness and a white grape note that lingers in the aftertaste. It’s a great marriage of the mango-y flavor of Calypso, the clove-banana spectrum of Belgian yeasts, and Nelson’s forthright grape tones. The DMS issue may or may not fully clear, but we were aiming for a big IBU beer – it came in around 100 IBUs – that wouldn’t be bitter, and we hit that mark dead on.

Calypso and Nelson Sauvin are two great hops that taste great together, and I can’t wait to play around with them again.