Hoping to stay on focus and revitalize this thread a bit...
I've been working w/ this tek for almost a year now. I had a rough start but I kept at it and learned a lot through trial and error. Thanks Canndo for your work on this and sharing the knowledge. It's in that spirit that I offer up a few things I've learned while sticking to the prescribed plan:
1) having a not too soggy substrate AFTER pressure cooking has as much to do w/ the water in the cooked popcorn as the water level in the pressure cooker. You want the water in the pressure cooker to be almost completely evaporated when the time is up for sterilization. This seems to ensure (correlation) that there is minimal water in the jar as well. I think it's an equalization thing but I've noticed over and over that if there's too much water left in the pressure cooker, there's also too much water left in the jars. Extra liquid slows mycellium growth and ensures contaminates.
2) a glove box GREATLY increases your chance of success. I call it a glove box so you know what I'm talking about but my box doesn't actually have gloves attached to it. I wear vinyl food service gloves, wipe out the box, the table, my gloves and outside of the jars w/ isopropol alcohol. The box is a clear plastic tote w/ two holes cut into it side for my hands. It took 5 minutes to make and negates the need for all steps related to air flow in the house and spraying down the room w/ disinfectant. You're essentially creating a sanitized, tiny work area that is no larger than it needs to be. When I'm finished, the tote doubles as a storage container for all my supplies.
3) after injecting the substrate w/ spores I replace the lid and immediately tumble the popcorn kernels. In doing so, the spores are dispersed evenly throughout the substrate. About a week later w/o any shaking of the jars, I have a half colonized AND evenly colonized jar. I then break out my "glove box" again, open the jars, pour out the CO2 and the next day they explode w/ growth. 4 days later they're ready for casing.
I'm still learning about optimal misting and humidity in order to get dense pin sets... Lots MORE to learn here...
Thanks.