I don’t think you want your mushrooms made into a super fine powder, because of that mud. If you have courser particles mixed with the finer particles, it allows better drainage. it’s like adding sand or perlite to plant soil to create pockets around which water (or ethanol) can flow. 

I’ve noticed this as well. Weird nodules, forming on the caps, as well as yellowing on the stapes.  I think it’s an indicator that you don’t let your humidity cycle low enough to dry off the surfaces before you re-humidify, at least that’s what I’m telling myself. Honestly I’m not sure!! 

We’ve been getting complaints from restaurants about creepy caps too

How the rotten hell do you shred and powder reishi without absolutely obliterating your blender? Even a blend tech which runs at 1800 W struggles.

This is a great idea.  To take it even further, it would be interesting if there was some auto clave resistant Indicator that we could add to our substrates pre-sterilization that would change colors or fluoresce when certain contaminant species were present.