For some reason, I've been brewing for over a year, & my scoby is getting stronger & thicker, but last time & now I split the top layers is scoby from the bottom. Last time the new top layers fgot moldy. And I am trying again, and little white pieces seem to form, which is what happened last time. But same recipe & my older scoby keeps brewing just fine. I'll try to attach a picture. Just trying to create another strong backup scoby, I've given plenty away in my small sized mason jars, those scoby a seem to do fine. Perhaps I need to add extra old kombucha starter liquid at the top? Just creeps me out the rest does so well, hate to waste all that tea & see it go bad!! Thanks for all help!!