Very slow growing scoby

Hey all, I got into brewing kombucha a couple months ago. I got a bottle of commercial "raw" kombucha and slowly built it up to 1 gallon size batches. I started with 10oz, then 20oz then 40oz then finally gallon.

I am now getting a nice tart, great tasting beverage. However, I am getting very little scoby growth between batches and am still using the original scoby. My first gallon batch I let go for three weeks. a slight film grew on the surface in the first week and grew just a bit over the next couple weeks. Maybe 1/16" of an inch thick. I bottled 80% of the liquid and dumped a cooled fresh batch on top of the existing scoby (which now looked like globs of stringy goo due to interrupting the liquid). I let the second batch go for two weeks, because three weeks was just a bit too tart. The film grew a bit faster, but still was around a 16th of an inch thick. Third batch I dumped on top of the sad-looking scoby, sediment and all. We'll see how this batch does.

I am getting a lovely tart beverage and am noticing zero mold growth so my kombucha must be doing its thing. The scoby just doesn't look right. Plus I am getting very little fizz, even with 2 weeks in bottle at room temperature. Any thoughts?

@ What temp are you keeping it. I also I grew a scoby from a commercial bottle of kt. It took about 10 days to get to a 1/4 inch in 82 degrees. After that I did my first gallon batch. Now I have a 3/4 inch scoby and I split a baby off to start a scoby hotel. But this was after 3 batches now am currently on my 4th.

The first couple batches were between 75-85 degrees, now it's more like 70-75 due to temps cooling down. Sounds like you had better luck with choosing a good bottle of KT. Researching a bit, I am finding out most of the (even raw) commercial stuff has additives that make it hard to propagate. Oh well, I'll keep growing the same scoby until it either actually gets more than a 1/4" thick or until it completely dies or grows mold. :shrug:

Agitation of the jar will cause the scoby to sink and start anew, when checking out you brew handle gently, I wonder even about keeping stored on the fridge because of the potential jarring during opening and closings.

When using an acknowledged amount of finished starter kombucha, I believe 10% is common or less if using a boiled natural cider vinegar, to acidify the tea to be receptive to the yeasts and bacterias we are hoping to propagate and not so much advantageous bad guys, I think you want to consider how acid your starter is and maybe cut back a little if it is veRy tart.

Chlorine family member treated water, some of which don't evaporate out well, are going to inhibit good as well as the intended bad bacterias, filtered water for brewing may help. I don't know haw hard water may work, I live where the water is soft and run it through a filter to remove municipal chemical treatments

Not all acetobacter produce good pellicle. The KT you started with may lack the strains that build the SCOBY. As long as the tea comes out right, don't worry about it.
If you would like to try, start a SCOBY hotel and leave it undisturbed for weeks. Don't fill the jar just have a couple cups (500ml is good) and every few weeks add another 250ml of sweet tea. This jar is not to harvest. You'll be making strong starter and hopefully attract some more bacteria that like to build, from the air. Try using distilled water. Tap water has a lot of crap you don't want in it. Even filtered water still has all kinds of nasty stuff like fluoride in it. Distilled, RO, or spring water from a trusted source are your best ingredients.

Thanks for the suggestions, I will keep doing what I'm doing for now.

I will try distilled water for the next few batches. We have really good tap water, though there is some chlorine and it's very hard, mineral-wise.


If the no-SCOBY thing keeps bothering me I will just order a proper culture. Amazon has them for around $10. Might make a good Christmas present.

Get on facebook and look for a group called Kombucha Nation. You should be able to score a good scoby and starter for only shipping costs.

Thanks for the suggestion kyt, I will likely go that route! A proper SCOBY and better water will likely make a big difference. :cheers: