I watched a Science channel segment about mold and spores. They showed how to make Tempe which is fermented beans. I image this is the same way the factories make Shu. They mentioned Aspergillus Niger used in Puer in other fermented products. The presentation included a professor in the NorthWest who travels the world look looking for mold and fungi which he stuffs in his Santa red hat. I think I can track him down. I'd like to ask him what he knows about Puer.
Jim