Why does a new SCOBY form every time?

[Canyx]

Hey all, new brewer here! I actually don't have any questions regarding the brewing process; things have been going smoothly so far but I'll be sure to search through the forum if any problems arise.

My question is more general... I've always wondered why a new SCOBY forms each time you brew, as opposed to just having the mother colony get bigger. Any insight?
Thanks!

 

[kyt]

I don't know the complete big picture here, but part of the reason is to seal off the solution from invaders and environmental contamination. It's like a skin that is grown to protect the colony. If you are able to float the mother, the new layer may adhere to it.