Kombucha is traditionally made by fermenting teas starting with a SCOBY, or Symbiotic Culture Of Bacteria and Yeast, a collection of microbes that reproduces indefinitely via sharing of metabolites and encasing the entire culture in a cellulose biofilm. If obtained from someone who has been fermenting kombucha for several years or longer, the SCOBY can be a rich and varied source of microbes, both fungal and bacterial.

But here is a simple workaround that can get you started that costs almost nothing. It won’t have the same diversity of microbes as kombucha brewed from a SCOBY that has survived numerous generations, but it will nonetheless contain interesting microbes. And, if you generate your own self-perpetuating kombucha, you never have to purchase a starter source again.

We start with a commercial kombucha, preferably one with multiple microbes that include Saccharomyces boulardii that is the main producer of carbon dioxide effervescence, and the very well-characterized Bacillus coagulans GBI-30,6086 spore-forming microbe. The GT brand* is my preferred starter (around $3.50 for a bottle), as it includes these two microbes, as well as unspecified Lactobacillus species (likely of the room temperature-fermenting variety such as L. brevis and L. plantarum, unlike many of the Lactobacillus species we ferment as yogurts that “prefer” higher human body temperature). Alternatively, you could start with Cutting Edge Cultures Kefir Soda starter** that contains Leuconostoc mesenteroides, Lactobacillus delbrueckii, Bifidobacterium longum, as well as Saccharomyces boulardii.

Green and black teas provide their own collection of health benefits, such as cross-linking mucin proteins in intestinal mucus, converting mucus from a semi-liquid barrier to a semi-gel and thereby affording better protection of your intestinal lining against bacterial toxins. This is why green tea is a component of my Clove Green Tea recipe from my Super Gut book that helps heal an inflamed intestinal wall as you work to reduce pathogenic species and replace with beneficial, mostly butyrogenic (butyrate-producing), species.

While I’ve cultivated conventional kombucha in past, maintaining the SCOBY over time. I wanted to see if you could make kombucha with the convenience of starting with a commercial product you can buy in most supermarkets, absent the SCOBY. (The presence of the SCOBY is obvious, as it looks like a thick pancake floating at the top of the liquid.) I made a batch this way using organic strawberry mango black tea bags, 3 bags to a quart of boiling water. I allowed it to steep for 5 minutes, then added 4 tablespoons of sugar. (Don’t worry about the added sugar—the sugar is consumed by the microbes we are going to add. The final product should contain little to no residual sugar.)

Allow the mixture to cool to room temperature—very important. Adding the microbes too early will kill them. Add a couple of tablespoons of commercial kombucha, such as GT brand. Allow to sit on your kitchen counter for a minimum of 5 days, preferably longer. It is important to keep the cap somewhat loose, or to vent by loosening every few hours, or using a venting cover (available in beer brewing  stores at low cost) in order to release the carbon dioxide (CO2) gas that is produced.  We take this precaution to prevent excessive buildup of CO2 that, if unvented, can cause your mixture to explode and make a huge mess in your kitchen. So allowing the CO2 to escape is important.

You can taste a small quantity of your kombucha after a minimum of 5 days to ensure that you cannot taste much sweetness. You do not want to be exposed to sugar, of course. If some sweetness persists, allow to ferment longer, say, another 48 hours. To keep your kombucha going after you’ve drank some of it, top off with more cooled brewed tea and another 2 or so tablespoons of sugar. You can keep this brew fermenting perpetually, conceivably for decades. While my mixture has been going for no more than one week, I would like to see if a SCOBY eventually forms. I believe it will, judging by the particulate matter that appears to be accumulating at the surface.

Add a fermented food like kombucha to your efforts to cultivate healthy bowel flora. Key is variety—also get kefirs, yogurts (of the sort we make using extended fermentation, not the stuff sold in supermarkets), kimchi, fermented veggies, etc.—because that is how we generate species diversity. While the microbial species of fermented foods do not, in general, themselves take up residence in your GI tract, they provide metabolites to important, mostly butyrogenic, species (a phenomenon that microbiologists call “cross-feeding”) such as Faecalibacterium prausnitizii, Akkermansia muciniphila, and various Bifidobacteria, Lachnospiraceae, Ruminococcaceae and Clostridia species.

*I have no relationship with the GT kombucha company. It’s just a cool product.
**I am a paid consultant to Cutting Edge Cultures.