Kombucha 101: Grow your own SCOBY
I remember the first time that I tasted kombucha, a fermented tea beverage. I was at a trade show for the specialty food industry with my mother and some brand representative thrust little cups of this exotic, fizzy, tea beverage into our hands as we walked down the aisles of vendor booths. We each took a sip, turned to one another with expressions that communicated our displeasure, and deposited our little cups into the next trash receptacle down the aisle. This was about fifteen years ago and I have no recollection what brand we were trying, why we found the taste so unpleasant, or how I came upon kombucha again with a more open mind years later, but it is now one of my very favorite beverages to make and to drink.
For those unfamiliar with kombucha, it is a beverage made by introducing a symbiotic culture of (good) bacteria and (good) yeast (known to its friends as a SCOBY) into a batch of sweetened tea. The SCOBY feeds off of the sugar in the tea and releases carbon dioxide throughout the fermentation process, creating a bubbly brew. The fermenting process allows the yeasts and bacteria to multiply into the tea, yielding a probiotic elixir that can do all of the wonderful things for the gut that we have come to understand and expect from probiotics. (See this article for a bit more about which probiotics have been found across kombucha samples). As we have also been learning more about the important connection between our gut and our overall immune system, kombucha may represent another way to introduce robust probiotic populations into our diet and into our gut, resulting in an overall healthier immune system.
I had become interested in kombucha once again when I began to learn and think more about cultured foods as the kids advanced through their Waldorf school. Part of the parent education piece in preschool included discussions about diet and the gut, and featured a lot of conversations about Sally Fallon’s Nourishing Traditions, as well as Weston Price, both of whom emphasized cultured foods and gut health. As I played around at home with sauerkraut and other cultured vegetables, at some point a bottle of kombucha made its way into my cart at the health food store. This was a bit odd for me as I am a water and hot tea drinker by nature. I really do not enjoy any other beverages and am not inclined to experiment with them often. That said, I loved the refreshing bite and bubbles in kombucha, and it quickly became another preferred way to hydrate and refresh.
As any regular kombucha drinker knows, a kombucha habit can become costly to support as bottles can run upwards of $4-$5 each at the store. Moreover, although the selection of available kombucha options is ever-expanding as kombucha’s popularity soars, one is still limited to the flavors available at their local markets. Fortunately kombucha is very inexpensive to make on your own, especially once you get your basic ingredients and set up ready to go (i.e., loose tea, organic sugar, good water, a brewing container, bottles, and of course your SCOBY). I knew how to source out the basic ingredients, but finding a SCOBY can be a challenge. I was lucky because one of the teachers at the school at the time brewed her own kombucha regularly and thus had SCOBYs to share (each batch will yield a new “baby SCOBY” in addition to the reusable “mother SCOBY”). I used the SCOBY that I was gifted and its resulting babies to brew and share for years. Unfortunately, with our move and extended time living in someone else’s home, I could not maintain my brewing or my SCOBYs. As soon as we got into our new house, brewing kombucha was high on my list of things to do right away, but despite asking around I could not get my hands on a new SCOBY. I considered several options (purchase one online, drive a distance to a store that sells them fresh, etc.) but in the end I opted to just grow my own.
There has been a fair amount of debate in kombucha brewing circles for a while about the feasibility of growing a SCOBY from store-bought kombucha. I participate in an active kombucha-brewing discussion group and this topic pops up a lot. Some of you may recall that a number of years ago, Whole Foods sent a panic out to their kombucha-drinking customers when they pulled all of the kombucha off of store shelves for months due to concern that the alcohol content in these beverages may have exceeded the 0.5% threshold that distinguishes “non-alcoholic beverage” from “Mommy can’t drink that in the car on the way to yoga class.” As a result of this debacle, many kombucha manufactures modified their brewing practices. It has been speculated that these changes in the brewing process have somehow altered the viability of the kombucha in such a way that it hinders the growth of a SCOBY. The general consensus is that if one is attempting to use store-bought kombucha to grow a SCOBY, they should look for a bottle that is clearly labeled “raw” and that has no added flavoring agents, like juice. To grow my SCOBY, I purchased a 16 oz. bottle of GT’s Original Organic Raw Kombucha. For good measure, I looked for one that had a lot of “gunk” in the bottom of the bottle (which I think is technically yeast, not gunk, but nevertheless having more seems to jump start the process).
There is not much that is required to grow a SCOBY, but it is important that you keep everything really clean. Because you are working with a fermentation process, you don’t want to have bad fungi or bacteria hanging out and proliferating along with the good. Accordingly, you want to make sure that you use a sterilized, clear, non-leaded glass vessel to grow your SCOBY or a sterile ceramic fermenting container. DO NOT use a plastic container or any glass with additives such as colors or metals as chemicals will leach into the tea and SCOBY during the fermentation process, which means that you’d be sipping toxins with your tea and we do not want that. I used a quart size glass canning jar that I sterilized in my dishwasher and immediately removed to put to use as my SCOBY incubator. You can also sterilize your glass jar in boiling water, in a low temperature oven, etc. I would recommend using a large-mouthed jar if possible to allow for the best air flow and surface area for SCOBY growth. The SCOBY will grow to the exact circumference of the container and you want a good size SCOBY for future batches. Also, if the top of the container is more narrow, it can be tougher to get your SCOBY out of the jar in one piece when you are ready to make your batch of kombucha.
Once you have your sterile glass jar all clean and dry, just open up your bottle of kombucha and dump it in. It’s that simple. You are going to want to let your kombucha breathe while it works to grow that SCOBY since it needs to keep taking in oxygen and releasing carbon dioxide. That said, you don’t want your jar open to all of what is floating or flying around in the air. I generally cover my jar with a scrap of clean muslin or cotton. In a pinch a scrap of an old (clean) cotton shirt will work, or in the case of having just moved into a new house and not knowing where anything is, you can use a piece of a clean paper towel. Secure your cover to the jar with a rubber band, string, or the band of the canning jar lid (without the lid piece). Next you just want to place your SCOBY jar in some out of the way place. Not too cool or too hot, and not in direct sunlight. You also want to be mindful of the need to breathe, so a counter top is good, but a closed cabinet is not. In my experience the kombucha does not like to be jostled about, especially in the early stages when a new SCOBY is growing. If you do it will disturb the SCOBY growth, which happens along the very surface of the tea. This may cause the growing SCOBY to drop down from the surface and a new one will have to start growing all over again (not a critical error, but annoying). So it really is best to find some out of the way counter space for your SCOBYs growth process, which can take from weeks to a month or so.
The following photos show my SCOBY’s progress:
Here she is after about three days. Not a whole lot going on.
Now we’re about a week in. You can see a thin film starting to form on the surface. That is the new SCOBY growing. From the top it looks a bit patchy, which sometimes makes people freak out (they think that it’s getting moldy). If it is fuzzy, blue, green, or black you may have a problem; but slimy, white, brown, or tan are typical SCOBY traits, and those patches will expand and grow together to make the complete SCOBY surface.
It’s been about 19 days. SCOBY is starting to thicken up. You can see a couple of layers because there were two occasions when I jostled or moved the jar a bit
because I was trying to get a better angle for taking pictures for demonstrative purposes to show you what it would look like. I also was worried that there might not be enough sugar in the tea to support healthy growth, so I added about a teaspoon of organic sugar to it and tried to push down the edge of the SCOBY gently with a clean straw to allow the sugar to dissolve into the tea. The new SCOBY just continued to form over the layers and they had not totally separated from the top so no biggie.
Day 30 (today)!!! I can’t believe that it’s been a month already. I really should have unpacked more by now, which has nothing to do with the topic at hand, but goodness a month already!?!
The SCOBY is not quite 3/4” thick and is very pretty, if you’re into that sort of thing. You can see some of the CO2 bubbles trapped below the SCOBY and some yeast “gunk” hanging off the bottom of the SCOBY to the right. I will be brewing up my first batch of kombucha with my new SCOBY soon, as well as using the remaining tea in the jar as the starter tea for the batch. It is still a small SCOBY, so I will need to brew a relatively small batch, but it will get the job done.
If you want to join me in kombucha brewing, start growing your SCOBY now and get your hands on some organic sugar and non-flavored, loose leaf, black tea or you can blend black, green, and/or rooibos tea (unflavored is a must though). You’ll also want a larger non-leaded glass container for your larger brew. I use this type of jar without the lid. They are often sold in 1/2 gallon, 1 gallon, or 2 gallon sizes at stores like Target. Hold onto that kombucha bottle as well because it will come in handy when you are bottling your homemade brew. We’ll talk more about the “why”s of all of those specifics next time, but just trust me for now.
Have you ever brewed your own kombucha at home or grown your own SCOBY from scratch? If you have any tips or favorite flavor combinations to share, I’d love to hear them.by