THIS CITY RECENTLY experienced a shortage that left me scouring the shelves of health food stores and grocery boutiques from Ocean Beach to Dolores Beach. Even now, when bounty seems restored, I mentally note obscure supply points in case there's a future run on my favorite source of "the tea mushroom," also known as "mother": kombucha.

My first purchase of G.T. Dave's Gingerberry (a blend of kombucha, ginger, and blueberry juices) probably occurred because I was hungover or anxious, or both. Blueberries, real and imagined, have a magical, calming effect on me, and their blue-purple shapes, succulently and faintly psychedelically popping out on the hippie-esque (pre-post-millennium redesign) label of this drink, had my hand reaching into the glass-front fridge for the nearly $4 bottle before the rest of me even knew what was up. Now I'm hooked on the tart and effervescent tang. Gingerberry and I are pretty involved; the other night a lounging friend found an empty bottle in my bed. But I'm flexible. When Gingerberry's hard to come by, I'm pretty keen on Gingerade, or even plain Original (kombucha all the way).

Who knows whether the buoying effects of this elixir are due to drinking the actual "enzymes – probiotics – detoxifiers" the label lists or to the psychological effects of drinking in the words? I mean, who isn't all for "cell integrity" and "liver function"? Gingerberry's key ingredient, kombucha, a mysterious substance, was filed under "health craze" in my brain, soon after oat bran, chronologically. I thought it was a Chinese mushroom, but it's not. It's a symbiotic colony of bacteria and yeast. And that's as much information as I could get, so far, in terms of its true makeup.

Kombucha's fans accord it myriad virtues – from cancer-fighting properties to effectiveness as an underarm deodorant, not to mention rust remover. Don't scoff until you've scoured, I say. "To learn more about this "tea beast" – so known because it reproduces quite enthusiastically and feeds on tea to do so, enjoy the Web site www.kombu.de, where kombucha's nature and nurture are extolled in twenty-nine languages, including Esperanto.

As a fermented drink, kombucha's kind of like a pickled tea. Two great tastes.... Fermentation, were it vocal, could lay claim to being a building block, or maybe even a cornerstone, of civilization. Were it not for fermentation – through which living microorganisms not only preserve perishables of all sorts but also make them more digestible and nutritious – we'd probably not have made it this long, for better or worse.

It started with free-floating, "wild" bacteria and yeasts, et cetera, having their way with various foodstuffs, resulting in yogurt, kefir, sausage, cheese, kimchi, miso, pickles, beer, wine, coffee, cocoa, and [add more beloved comestibles here]. Distinctly local microorganisms contributed to producing cheeses, wines, et cetera, whose flavors were specific to particular localities. It wasn't until Louis Pasteur came along, in the 19th century, that we really got a handle on the science of the fermentation process, which in turn made mass production possible.

The other night I reclined, munching on kimchi from Clement Street and washing it down with (San Francisco's own) Prince Neville's Jamaican Ginger Beer, while also relishing "Cultural Context – The Making of a Fermentation Fetish," an early chapter from Sandor Ellis Katz's manifesto and ferment-it-yourself bible, Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods. A self-confessed fermentation evangelist, Katz makes the point that eating the fruits of wild fermentation – that is, fermentation that results from the microorganisms in our own immediate environments – promotes biodiversity: "microbiodiversity." "Your body," Katz writes, "is an ecosystem that can function most effectively when populated by diverse species of microorganisms.... [By] fermenting foods and drinks with wild microorganisms present in your home environment, you become more interconnected with the life forces of the world around you."

Though mainstream concepts of dietary health don't (yet?) reflect Katz's perspective, the benefits of eating fermented foods are widely acknowledged, if mainly in the arena of digestive health. A growing number of products are being marketed as "probiotic," which literally translates to "for life," the idea being that fermented foods contain "good" bacteria ("live, active cultures," as your yogurt label may say) that help the body fight "bad" bacteria and keep your microflora healthy and in balance. Not that far from Katz's conception, it seems.... One can buy "probiotic" supplements that contain assorted microorganisms commonly found in diverse fermented foods, such as strains of Lactobacillus, Bifidus, and Streptococcus. Lest the reader think this a fringe market: ConAgra Foods has had a probiotic supplement, Culturelle, on the market for seven years now. Culturelle contains a patented bacteria strain, Lactobacillus GG, which the company touts as the "most extensively researched and clinically proven strain available." Essentially, ConAgra claims that Culturelle provides a viable probiotic, meaning the human digestive process doesn't do the bacteria in, so that it actually survives to do its job. In general, questions remain about how to introduce probiotics into the body effectively: What foods or supplements, and in what amounts, produce positive results?

What can be said for sure about us, here – participants in the culture of mass production and consumption – is that we don't eat much "live" food. Most fermented foods for sale are treated in ways that ensure the absence of bacteria, bad and good. A quote from ConAgra's Culturelle Web site sums up our prevailing mindset about microorganisms: "Yes, there is such a thing as good bacteria!"

Me, I'm a little germophobic, but I'm very pickle positive. Surveying the state of my kitchen, I'm convinced it's packed with pickle-producing probiotics. Biotics of many sorts, without a doubt. Pasteur supposedly said, "It's the microbes that will have the last word." Right after the cockroaches, I suppose. If you can't beat 'em, join 'em – or have them join you.

E-mail Masha Gutkin at lydialeapfrog@yahoo.com.