If a second, new Scooby forms during fermentation, should I use this one in the next fermentation?Updated a year ago

With each brewing cycle, the vitality of the scoby decreases more and more. After 20 brews, you should definitely use a new Scoby. It's a good thing that new tea fungi keep developing until then. Of course, you can still use your "original" fairment Scoby for a while and put the new one in the fridge with some preparation liquid as a "back up".