I live in the most contaminated part of the country when it comes to airborne molds and such, and one of the ways I've managed to be successful here anyway is by sheer speed (outrunning contaminants). It's part of why Stamets' latest book was titled Mycelium Running.
The slurry tek is one thing that helped me accomplish that, along with massively-increased pasteurization times for my bulk subs which are either 100% straw or a blend of straw and Hpoo (I've gone almost completely to 100% straw grows in recent years). I hold my substrate at pasteurization temp for ~12 hours before turning off the heat and letting it cool slowly (my pasteurizer is insulated) for about 18 hours. It stays over 150F for another 8-10, usually, which is why it takes so long.
Once I switched to the very long pasteurization time my issues with contamination dropped dramatically, particularly in terms of multiple flushes (I have some ideas as to why but that's getting way off-topic).
The next thing I changed was adding positive-pressure HEPA-filtered ventilation. That's not easy, and I did it by repurposing my first flow hood into doing that (it was 12"x24"). But it's definitely worth figuring out how to do something similar if you can manage it, (it only actually helps if you keep the grow room impeccably clean all the time, too of course). Even then I can't really grow in the Summer (or much of the Fall) where I live since air conditioning would be required and air conditioners are mold factories (it's a really tough and underappreciated problem for a lot of home growers).
If you've not worked in front of a flow hood before then getting one and going right to the slurry tek will involve a short but steep learning curve. It's not difficult in a technical sense to do, but there is a lot to keep in mind while you're doing it (sterile technique 101). Making the stuff might be a hassle though, depending. But it's cheap!
One of the many things I like about the slurry tek is that I don't have to bother with agar or LCs or isolates at all. It's literally just taking a PF Tek style cake started from spores, turning it into mud with a sterilized blender, and pouring the mud into jars or bags of grain. My thread detailing how to make it seems a lot more complicated than it is to actually do it. I tried to cover as many bases as possible for those who don't often make stuff like that.
The catch with using a slurry is making sure nothing else slips in while you're making and dispensing it, and a flow hood makes that relatively easy but is expensive.
A nice big SAB (still air box) works for this too while being considerably less convenient to work with but is also exponentially cheaper and easier to acquire.
A full mycology lab (for a home, that is) needs both, actually, so if you start now with a SAB and later get a flow hood you'll be all set to expand into other stuff (other active species, gourmet edibles, etc.) if you want. The more of this stuff we do, the more we tend to want to do (it can get obsessive; you've been warned!).
Oh, and last thing to mention is that when you do start a new approach or method, don't switch over 100% to it. Do some smaller-scale trials and get it working consistently before doing that. There's always a bumpy transition period between theory and practice, I've found. In theory that should be something we can eliminate, but in practice we can't.
Good luck!
), is one of the major things we're trying to control when prepping grain/sub. So adding extra can become very problematic.
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