[vbezhenar]

Do you have any reference? I don't think that's strictly true. I agree that this big slab is just some kind of protection, but if you would look at the bottom part of this slab, you would see threads, like small seaweed which "grow" from this slab. My understanding is that kombucha is a symbiotic mix between those threads (it's actually Yeast fungus) and bacteria in the liquid. Liquid does contain some parts of fungus, of course, so you can throw out the entire slab and new slab will grow eventually, but you're throwing lots of yeast and its protection. So your kombucha will take much more time to brew and final result will not have the same proportions of components as "properly" brewed kombucha.

[ValentineC]

> My understanding is that kombucha is a symbiotic mix between those threads (it's actually Yeast fungus) and bacteria in the liquid. Liquid does contain some parts of fungus, of course, so you can throw out the entire slab and new slab will grow eventually, but you're throwing lots of yeast and its protection.

On the other extreme: if one has an old enough continuous ferment, a lot of yeast will settle at the bottom, potentially affecting the end result.