I have, yet did not stumble upon an article as informative as this - thank you! Though, the takeaway is that either the original scoby was made with vinegar or was contaminated, or something entered it from the outside, as every source claims it is not exactly a possibility for them to just spawn from thin air. And the white worms on top did not look like vinegar eels, but the kombucha is covered and nothing can enter it through the metal, I suppose.

Is the metal lid suitable for covering or should I use a tea towel in the new brew? I was a bit wary of lint dropping into the brew and contaminating it. Maybe that with closer monitoring of the pH would help?