On Nutrition

Living in Seattle, I thought kombucha was ubiquitous — you can find it everywhere from craft cocktail bars to Costco — but when a friend from Washington, D.C., recently asked about it with a touch of skepticism in her voice, I realized it’s far from mainstream. I suspect my friend’s skepticism stemmed from simple unfamiliarity and kombucha’s health-food reputation — she has a robust B.S. meter for unsubstantiated health claims.

Kombucha, for the uninitiated, is sweetened black, green or oolong tea fermented at room temperature with a mat-like SCOBY, short for “symbiotic culture of bacteria and yeast.” During fermentation, this mixture of live cultures consume — or ferment — much of the sugar in the tea, turning it into a tangy, fizzy beverage that can be flavored with juice, herbs or fruit. After my first sip of kombucha several years ago, I thought, “Hmmm … this tastes a little like vinegar.” After my second, I thought, “Yes, I definitely like this.”

I’m a fan of kombucha’s lightly sweet-tart flavor, but not its health halo, which became deeply tarnished in my opinion after I watched a health-conscious acquaintance with an eating disorder shrink before my eyes while proclaiming kombucha their favorite “food.” But that’s an isolated example, as are the few reported cases of people experiencing negative health effects after drinking kombucha. These situations were caused by things like drinking WAY too much kombucha, not storing it correctly, or failing to practice good hygiene when making it at home.

The fact is that the bacteria and yeasts in the SCOBY work quite well together to inhibit the growth of potentially harmful microorganisms. The same is true for other fermented foods, including sauerkraut, kefir and sourdough starters. Even the Food and Drug Administration states that kombucha is safe when properly prepared and handled. Keep in mind that the fermentation process produces ethanol — alcohol — which may or may not be converted to acetic acid as the process continues. Kombucha with alcohol levels of less than 0.5% can be sold as nonalcoholic, but varieties with more alcohol than that must be labeled with the same health warning as any alcoholic beverage.

What about the health claims? Does kombucha really boost intestinal health, immunity and mood? Does it help protect against cancer and heart disease? From a scientific point of view, the hype here outweighs the evidence, much of which comes from studies in rats or petri dishes, not humans. But those studies do suggest that the antioxidant and potentially cancer-fighting properties of tea may be heightened during the fermentation process. That said, kombucha is also touted as a probiotic even though the particular mix of microbes varies from batch to batch and doesn’t meet the scientific definition of “probiotic,” and some of the newer “hard” versions are pasteurized, killing off any live, active cultures.

Buying kombucha can become an expensive habit, but making your own is not. DIYing does require attention to good food safety practices as well as a bit of babysitting — the SCOBY, much like sourdough starters and kefir grains, is a living thing, after all. Either way, I think kombucha’s best use is as a mocktail — it tastes more special and feels more satisfying than sparkling water — so if you enjoy the taste, go for it. Just don’t view it as a magic elixir.