Kombucha has dark, green grey dust/moss inside liquid

Question

Some of my kombuchas form a strange, greenish-grey powdery substance inside them. This looks like moss or dust, and appears embedded in the transparent matrices of strands inside the liquid, although many of them sediment to the bottom as well. This substance is exclusively inside the kombucha liquid, given that the rule of thumb is that "mold grows on top only", I assume it's not mold. I have also tasted this kombucha before and it tasted ok, I didn't get sick or otherwise impaired.

I tried washing the green strands off the SCOBY (they were hanging from the underside of the baby/daughter). But the next batch still developed the same growth.

Kombucha Kamp has a picture very similar to my issue. They claim it is not mold, but "tendrils of yeast".

If this is yeast, how come it's so dark in color? I thought yeast had a yellowish-white color. What are they? Are they dangerous? Are they bad? Can you stop them? Why don't all my kombuchas have it?

I can post a photo if anyone is interested, but it would look practically identical to Kombucha Kamp's photo.

Answer 1

When I grew Kombucha it looked quite like the pictures supplied. Kopmbucha is a SCOBY that does not conform to any one typical shape or colour pattern. I have often heard the growing SCOBY compared to an exotic "jelly fish". I have also heard it said that different colours can develop with different fermentation basis. Some of the colours are definitely pH dependant and change as the SCOBY produces more acids. Over time different organisms (bacteria and yeasts) can develop in the SCOBY these are rarely (if ever) dangerous but may bring some different morphologies and colours. Indeed the growth of the SCOBY can make biological assemblages that diffract or absorb light - which will alter the overall colour of the biome. The main point about a SCOBY is that it tends to "oscillate around a mean". It is rarely looks the same from week to week but it remains essentially the same thing. I suppose rather like LEGO bricks - one can arrange the components into a variety of shapes but they still retain the basic properties and functions whatever the whole thing looks like..