you do realise that you aren't sterilising anything though right? It's not a crap shoot - it's a unnecessary step since you aren't actually achieving anything. You might as well not do that step
You can get away with sterilizing your grain spawn because you keep it isolated in a sealed jar, away from environmental contaminants, until it is completely colonized by mycelium. But since substrate is exposed to wild molds and other ambient contaminants, it needs it's microbial defense team.
Straw is quite a hassle, it contaminates with mold super easily, and is and about 20 years out-of-date to current practice. Yes, the Stamets book calls for it. The Stamets book is old. Any advise older than about ~5 years in this field is questionable at best.
Most folk these days use coconut coir (shredded husk) as a substrate. It's cheap, convenient to ship and store, and it is more resistant to contaminant growth. Coir comes in compressed bricks, you rehydrate it in water just off boil, it expands about 10:1, then you psuedo-"pasteurize" by letting it sit in an insulated cooler for 2 or 3 hours until it is below 170F.
Do you add anything to the substrate besides npk? Which I assume you would use, but I don't know enough about mushrooms yet. And if you do, do you control the mushroom stages by different ratios of npk as well? Besides of course, inspecting them as well.
Mushroom cultivation is really remarkably simple, and the worst thing to do is overcomplicate it, like with this gadget. The hardest part for most people to learn is the sterilization/sanitation steps that are required in the early parts of the grow, but it's not much worse than home beer brewing. Fruiting is mostly regulated by CO2 levels / fresh air exchange, and the microclimate (humidity and still air) within the first few millimeters of the surface. Everyone thinks they can electronically monitor and regulate this, but it rarely works well, and the community has developed passive methods that work just fine and cost nearly nothing.
The minimum equipment list for practical growing is a large pressure cooker/canner (Instapot will do in a pinch), some mason jars, some plastic shoeboxes for fruiting chambers, and a big plastic storage box to make a "Still Air Box" (a poor man's laminar flow hood)
Ingredients for food/spawn can be as as simple as cakes made from brown rice flour and vermiculite. Some use wild birdseed, I prefer whole oats. Woodlovers get the cheapest wood mulch they sell at Home Depot.
Whether you are interested in psychoactives or just gourmets like oysters, I recommend people skip reddit/youtube and "Uncle Bens" pre-cooked rice junk, and head over to shroomery.org, an old-school web 1.0 messageboard that has been active since 1999. One of the moderators there has a list of up-to-date threads for getting started. https://www.shroomery.org/forums/showflat.php/Number/2414402...
I will check out shroomery, and see what the simplest and minimum amount of control feedback loops I can get away with using. If any, preferable passive as you say. Thanks!
One in ten/fifteen buckets with straw may get moldy but it’s still an order of magnitude cheaper.
[0] https://craftmetrics.ca/blog/2019/pasteurization-part-1-the-...