I haven't been able to find any information on this online. Kombucha recipes always suggest to either get a bit of the starter from someone else who makes kombucha or to grow the scoby from a storebought bottle, but both of these presuppose the existence of someone else's kombucha.
Some research:
- The SCOBY Wikipedia page does not give any history
- Neither does The Kombucha Wikipedia page
- This answer is related but suggests you need a lab to do it which I find unsatisfying
How did someone make the first batch of kombucha? Is it possible to make from scratch?