good site folks!!

am looking for some Aspergillus flavus var. oryzae spores aka koji -> thomas@biopilze.de

what i think ive understood about the koji-principal:

it should be feasable:
get spores on substrate like humid (NOT!!! wet) natural rice: allow to sporulate (before using make sure the color of the spore-lawn is evenly … if NOT: discard or extract just these evenly spots…) and extract JUST THESE next generation spores on fresh milled dry rice: this IS koji-starter now!!

the problem with Aspergillus flavus is:
they DO produce aflatoxins!!
BUT fortunately only AFTER MORE than three days inoculation time…!!!!

to transfer JUST the spores!!! avoids uptake of these aflatoxins safely as the spores itselves contain NO aflatoxins!!

so the trick is to propagate just pure-cultures of spores… AND ALWAYS!!!! finishing the koji-process after 72 hours max.!!!

well, if you can:
to work under sterile conditions would help BUT should NOT to be mandatory -i wanna try it out!!

ps
for tempeh ( mainly Rhizopus oligosporus / Rhizopus stolonifer / Rhizopus arrhizus ...) the system is analogue -though simpler-:
just buy fresh tempeh (if not pasteurized or freezed after production: let sporulate: means within about two more days under a rather warm and NOT TOO dry climate… you get a pure BLACK!!! surface: then you got a pure-culture: transfer these spores to freshly grinded rice: this IS your new starter already!!
maybe deeper insights you get by inspiration from e.g. Home made Tempeh Culture (Tempeh Starter), How to make a tempeh incubator and How to make Betsy's Tempeh (though, i wonder: sounds too simple, out of MY -long-years and bad- experiences with different fungi-pure-cultures-propagation: you DO run into bacterial blotch and/or concurrent molds or worse: maybe unreckognized aflatoxin builders that DO diminish the possible health benefits tremendously!?! -suppose that works for one or two generation only than fall back to bought tempeh-starter unless to stay at rather dry spores-propagation only...)

and far beyond: still more ...Culture-Foods of Asia...

ps ps
maybe you start a new post called:
koji-starter for shoyu, soysauce, sake, miso…

from Biotechnology Program under the Toxic Substances Control Act (TSCA):
> …Aspergillus oryzae is a member of the A. flavus group of Aspergillus species. The A. flavus group, which also now includes A. sojae, A. nomius and A. parasiticus (see below) is defined by the production of spore chains in radiating heads which range in color from yellow-green to olive brown. The conidiophores are roughened and colorless. The spores themselves have conspicuous ridges and echinulations (spines). Sclerotia are occasionally produced (Raper & Fennell, 1965). A. oryzae/flavus species have never been connected to a sexual or teleomorphic stage. However, the teleomorphic stages of other Aspergillus species have been demonstrated by the formation of cleistothecia. These species belong to the genera Emericella, Neosartorya and Eurotium, all belonging to the ascomycetous family Eurotiaceae (Fennel, 1973). Either the sexual stages of the A. flavus group have not been recognized as such, being identified as completely different species based on morphology, or this group of fungi are “degenerate”, having lost the ability to form sexual spores and mycelia… ... (u. siehe auch: epa.gov/oppt/biotech/pubs/fra/fd007.htm u. microbewiki.kenyon.edu/index.php/Aspergillus)