Kombucha culture for continuous brewing

Started my first big batch of kombucha today, which I will be maintaining with continuous brewing. Inspiration to start brewing came from a thread on the GotMead forums and the Mad Fermentationist blog; I hadn't realized how damn easy it was or I would of been brewing it years ago! (actually pretty similar to my starting homebrewing, haha!)

Ingredients for 1gal:
12 cups boiled water
3 tsps dragonwell tea
3 tsps assam tea
1 cup unbleached cane sugar
8 oz of a 16 oz bottle of High Country Goji Berry Kombucha
8 oz of a 16 oz bottle of GT Dave's Multi-Green Kombucha

Steeped the tea for at least 15 minutes. The amount of tea comes out to be ~1 teabag per 16 oz (ie half-strength) for those not familiar with loose tea. Used two bottles of kombucha to ensure a well-rounded culture, and I added half of each bottle to keep the acid levels high enough to keep the brew sanitary (I would have added 12 oz from each, but I realized after I put all the ingredients together that there wouldn't be enough room in the container I'm using).

I plan to keep this culture going continuously, trying different types of sugar and tea; especially looking forward to trying honey and matcha. At some point, I'd also like to use part of the culture for an alcoholic kombucha brew.

Very cool...post pictures!

mccann51 said:

trying different types of sugar and tea; especially looking forward to trying honey and matcha. At some point, I'd also like to use part of the culture for an alcoholic kombucha brew.

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Honey is a little slower to ferment, but is really good. I've also used black strap molasses and my favorite; maple syrup.
Fun to experiment with, but to be honest; now I just stick with the cheapest white sugar I can fined. The difference in taste is very minute, and the price well: $0.37 vs $4.99 for honey.

If you boil try to get some O2 back in the water once it cools. This helps the ferment.

I've always gone for a crazy strong tea, with a lot of sugar (about 1.092, or 20% by weight). This will make a really strong brew you can add to fruit juice or ice tea. (or sip like whiskey)

I don't know about the alcoholic thing. I think it's similar to a vinegar culture, and therefor would convert the ethanol.

I'll try and remember to get some pics, perhaps once there's some nice growth. Right now it's an opaque-ish grey-green from the Multi-Green Kombucha; hopefully that'll settle out so I can see what's going on growth-wise.

I did some vigorous aeration when I pitched the kombucha (probably at ~70-80F) to get some oxygen back into solution. I'll probably aerate tomorrow, as well.

I did one with some honey a few weeks ago (just a bottle) and noticed a mead-reminiscent taste. I decided to start this one off with cane sugar so I could get a baseline to compare with honey.

I was thinking for making an alcoholic version, leaving it open to air and then placing under airlock after ~0.5-1 week ought to do the trick. My understanding is that the acetic acid production is aerobic, but perhaps that is just for Acetobater spp and I'm mistaken about it's potential, I really don't know.

DrJerryrigger, how strong for the tea? Tsp per 8oz? I'd be down for that, I just wasn't sure if it would some how be inhibitory, though, since I haven't seen any recipes with that concentration. Also, if you up it to 20% sugar, does this all ferment? I'd be worried the high acid content might start knocking some of the yeast or bacteria out. I like the whiskey blending idea, btw.

mccann51 said:

DrJerryrigger, how strong for the tea? Tsp per 8oz? I'd be down for that, I just wasn't sure if it would some how be inhibitory, though, since I haven't seen any recipes with that concentration. Also, if you up it to 20% sugar, does this all ferment? I'd be worried the high acid content might start knocking some of the yeast or bacteria out. I like the whiskey blending idea, btw.

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I don't think I've ever taken note of how much tea... I always make it strong though. Stronger than you would want to drink as tea. It mellows, and clears a lot, so I don't think is possible to mess it up by using too much.

All the sugar ferments, I use a hydrometer to tell when it's done. It's slower to finish, but when cut with sweet tea, it has all the same flavors of the (pain) store bout one it started from, and this has held true over 5 generations.

I'm not saying my way is the best for everyone. The major drawback is the time it takes. But I like having the potent stuff around, takes up less space, easy to blend, probable could be used as oven cleaner...

I also like to make it in a few different vessels at the same time i.e. make 1 gal, and put it in two 1/2gal jars. This way if one molds; not all is lost.
The most important things are: keep fruit flies out, and forget about it for a few weeks.

Can't get the camera to work, but the SCOBY is a thin film right now that is all crumpled up in a ball - due to me swirling the container around to get some O2 and sugar into solution - floating at the surface of the liquid.

Started drinking down the kombucha from the first pitch a few days ago (so I guess it took about 10 days from dreg pitch to drinkable) and brewed some more tea up last night. Decided to make the tea stronger, so added a tsp of Dragonwell green tea for every cup of boiled water; let steep until the water was cool enough for the SCOBY (~45mins-1hr). Added 10 cups of tea total, along with 0.75 cups cane sugar to ~4 cups of kombucha.

The GT's Multi-Green left a lot of gunk in the brew; if I were to do this again, I would avoid it (the Multi-Green "flavor", not GT's brand).

I couldn't help myself. I threw in two cubes of oak from my sour culture; we'll see what happens.

The addition of the sour culture has not affected the taste in any appreciable way, which is good, since my basis for adding it was to get some Pediococcus in there in case I decide to play with some more complex sugars in the future.

I've done both dragonwell green tea and assam black tea batches at this point (both full strength tea, with 0.75 cups sugar per gallon, with ~1 liters kombucha remaining from previous batches). The dragonwell gives a less pronounced flavor in the end product, but it lighter and thus crisper. The assam gives more black tea flavor, and leaves a nice, full, round mouthfeel.

The tea is drinkable after ~4 days of fermenting now, and is too vinegary after ~6.

Will be trying different sugar sources soon.

I have a continuous culture going that I've been working with since Nov. I drink an average of about a cup a day (sometimes a pint, sometimes none). I found that blending was ok, but it was hard to notice much of a difference.

I should note that I'm using a 2.5 gal glass jug and a 1 gallon pitcher in the fridge. When the pitcher's empty I fill from the jug and brew another gallon of tea to add to the jug, keeping the jug volume right around 2 gallons. So at best I'm getting 1:1 dillution.

Another thing about continuous cultures I've noticed is that after about 2 months the mother gets too thick and "floats" above the liquid interface due to the gas evolved. It's because the thicker mother is rigid enough to seal to the sides of the jug. When this happens you have to push it back under the liquid or risk a mold problem. Usually when I notice this I drain the whole batch to bottles and clean the jug because the yeast cake at the bottom is getting thick as well. I separate off a few layers of the mother to put into a new 2 gallons of tea and chuck of gift the rest of the mother.

I like your approach with having the extra gallon put aside to make it a little more continuous (I guess I'm brewing more discontinuous, because I drain the gallon over a day or two, and then brew more tea, and then wait a few days til it's done fermenting).

I've definitely been having issues with my SCOBY floating above the liquid interface, as it acts as a gas catch and the CO2 (I presume); as it's getting bigger, though, I'm having the issue that you're talking about where it just acts as a giant plug. This morning I got up and found it was actually completely out of the tea and jammed up into the bevel of the jar! The yeast layer is getting pretty prominent in mine as well; I usually just mix-up the jar before pouring a glass to remove some of it, but it only helps so much. I'll probably take out the SCOBY soon and drain the bottom of the jar to take care of the lees.



I brewed a tea with some atypical sugar sources recently: it was 1:1 assam:dragonwell, full strength, and ~50ml blackstrap molasses, ~50ml brown sugar, and ~100ml buckwheat honey. I would have preferred to try each separately, but it's all I had of the former two, so the dark honey was just to bring it to a suitable amount of sugar. The final product was not great, though I can see it being an acquired taste (that said, I don't care to waste the time acquiring the taste). The molasses really, really came through in the final product with as a very minerally taste; it was a bit off-putting to me, and I had to wait til it was pretty vinegary for the taste to be balanced enough to enjoy drinking it.

My most recent batch I used all oolong tea. Again, the resulting brew is not great, though this may be because I didn't adequately mix the sugar in, so the tea flavor is coming through stronger than normal (I mixed it up today, so we'll see how it is in another day or two). The issue with the flavor is that the oxidized flavor of the tea is coming through really strong (I assume because of the extended steeping); the taste is nice in a regular cup of oolong because it's subtle, but here it's a little overpowering. Again, though, maybe it'll be good in a day or two once it's had the opportunity to ferment a bit more.

Next experiment will be with all orange blossom honey w dragonwell tea; I'm optimistic it will be delicious!

Hi! I'm reviving this thread in hope of getting some advice. I set up my first attempt at brewing kombucha about 3 weeks ago, and I'm not sure whether I need to adjust things or if I'm simply being impatient.

I am new to brewing, but have experience with other culinary microbiology efforts such as yogurt and bread baking. I think I've been sufficiently fastidious, but I know these things also have a mysterious feel, an "art" to getting it right and I'm trying to teach myself from the internet.

The Setup
I have a stainless steel 2 gallon continuous brew container, similar to ones marketed on kombucha enthusiast websites. We had been using it to dispense water. I washed it carefully, dried, and then rinsed with distilled vinegar to remove soap or chlorine or wild organisms. I do not have a SCOBY, so I bought 2 half-gallon jugs of locally made, raw, kombucha to use as my mother. Katalyst Kombucha (their Ginger Devotion flavor which is really lovely).

[argh, accidentally posted a fragment and as it's my first post, had to wait for mod approval, now editing in the rest.]

So. I bought two lovely half-gallon jugs of raw kombucha, drank about a pint glass off the top of each leaving all the nice sludgy stuff in the bottom. I boiled a gallon of water to sterilize, dissolved 1.5 cups of granulated sugar in it by simmering for about 5 minutes, turned off the heat and tossed about 6 packets of black tea in. Let it steep while cooling. Brought that down to 94 degrees by my (sterilized) cooking thermometer, and the kombucha up to room temp. I mixed about a pint from each of the cooled sweet tea and the commercial kombucha, noted the temp was in the high 80's, and then added the rest of each for a final volume of nearly 2 gallons, half each.

I topped it with a clean kitchen cloth and put a little warming pad under it, meant to help start seedlings indoors. Our house fluctuates between 63-68 degrees and with the benefit of the constant warming pad, when I measured the temp of the brew later on it was 72 degrees.

The Early Results
At ten days, a decanted sample was fizzier and sweeter than the commercial product. My brother was visiting and so despite its prematurity I decanted 25% of the total and replaced it with cooled sweet black tea.

At 18 days, it is tasting much more sour. It's near to drinking straight apple cider vinegar and no longer fizzy. There is an odd lopsided crumpled film over about 1/3 of the surface, a pale tan color. Not nearly as uniform or thick as I had expected a SCOBY mother to be. I do still enjoy tasting it (I have a taste for sour things) and from tonight's sample, I strongly suspect it is alcoholic as I'm feeling a bit of a buzz and I don't think it's placebo.

My Questions
Reading up, I suspect that I favored the yeast component too strongly at first, then let it rather overmature without feeding it bit by bit as a continuous brew ought to be fed. Some of the internet stuff suggests that letting it get too "sour" and sit a while might let the mother mature by favoring the bacteria, which synthesize the cellulose that forms the matrix of the SCOBY matts. Anyhow, if anyone has insight or tips about this, or guidance about how many weeks it takes for form a good solid SCOBY when starting from zero, or any other thoughts, I would appreciate your posts!