I've been using straight Brown rice, not flour no verm. Just cook it like you'd eat it and pack it into jars and into the Pressure cooker. I've had great results so far - no contams in the jars. Took only about 2 weeks to fully colonize set above my marijuana grow.
My last set of jars, I crumbled them into foil trays, and cased them with verm / coir. A week later I got pins, and today I harvested my first shroom
with more to come in the next day or 2.
Woohoo! Shrooms for New Years!
earlier this week I spawned 2 of my jars to trays of Coir / coffee. They're colonizing well now - so far so good!