I had be growing Kombucha with a friend ,usually on a blend of herbs such as mixtures of black,white and green teas with added ginko biloba,ginger and hibiscus.Some of them had so many herbs in that it would be easier to ask what was NOT in the rather what was.
Now, on the harmala issue: Harmala alkaloids might have antibacterial action so this could -theoreticaly- harm the bacterial section of your
SCOBY. Under this light, try keeping two batches, one "normal" with just green tea to revert back to it if things go south and the experimental one. I wonder if transformation of alkaloids to analogues will happen by the SCOBY of the Kombucha as part of its substrate metabolism.Interesting...
Also an idea could be to have a look at the brews fluoresence from time to time while brewing with a blacklight.Who knows...The fluoresence intensity/coloration might change? Will the scoby ,while growing, be infused with harmala alkaloids and glow under blacklight? Remains to be seen.
/me assumes "Generic Overly Manly Voice of Action Film trailers" :
By the makers of thriller "My Son got Kombuchered" and "Close encounters of the SCOBY type" the new film!
Lots ooooof ACTION!
"Did it...move? OH - MY - GOD! Its ALIVE!!!"
Stunning visual effects!
"Whoooooooah! It glows SO bright!"
Lots of suspence!
"House...Did you hear that? I think the sounds came from that jar..."
Intrigue,plot twists and conspiracy!
*in secret location,shady figures under the veil of darkness ,a voice is heard "We must intercept the sample...Someone found our secret, it seems to be evolving.Acquire it, burn or evidence and give me a chemical analysis ASAP.It might be the...Grand Elixir"
Soon,coming at a Home near you! "Kombucharma: It came from the ...tea"
(On a rather more serious note ,Don Amfiteatro's site on Kombucha is a classic gem :
http://users.chariot.net.au/~dna/kombucha.htm .Lots of info and experimentation! Be sure to pay a visit)