In search of: non-sterile mushroom cultivation tek

Continuing my investigations into the wonderful wild world of (non-wild) mushroom cultivation.

I had the presence of mind just now to take some photos as I run through my usual process of spawning onto oats.

This part I am super good at, continuing my mycelium culture indefinitely under non-sterile conditions. I started originally with a spore syringe (white oysters), grew them out on BRF cakes (brown rice flour) in my SGFC (shot-gun fruiting chamber) using the PF-Tek method. Everything is cryptic acronyms in the world of mushroom growing. “Tek” is how they say “technique”, but I’ve kind of come to like it.

Anyway, after my BRF cakes, which yielded very low sporadic results, I switched to live tissue samples (cloning) onto grains. At first, I was going through all the recommended steps of sterile procedure, glove box, wiping everything down with alcohol, flame sterilizing my scalpel — the whole nine yards. And originally, I was soaking my grains (rye and barley which I had at the time) for 24 hours, then boiling for 30 minutes, then adding my tissue samples.

After a little more than a week, I was ending up with results like this:

Which is pretty much what you want. Nice strong spawn run (the white stuff) throughout the the liter mason jar. A jar not unlike this, but 3–4 generations back, became my “grain master.”

My first G2G (grain-to-grain transfer) went fine, except it made me realize that my glove box is really too short to facilitate G2G under sterile conditions. I mean you can do it, but it’s just such a pain in the ass. And I wasn’t in the mood to go buy another plastic container to make a bigger glove box. Plus I’d heard open-air transfers could work, but they had higher contamination rates. I decided to give it a try.

Basically, once you have your master, you take it and slam it against a tire to break up the spawn so you can pour it into your next generation of jars. When you’re done, you end up with something like this:

“Pleurote” is oyster mushroom in French.

Anyway, since switching to this technique several weeks back, I’ve used it many many times and have had absolutely 0% contamination (knock on wood). I’m also not using any air filter thingamabob like they always say you’re supposed to in the instruction “tek” videos and tutorials.

I just take approximately (no need to be exact) 1 cup of dry grains to 2 cups water per each 1L jar you want to fill. Add some used coffee grounds (about a “scoop”) and some gypsum. I don’t actually know what the coffee grounds are supposed to do — boost it somehow? Probably you don’t need them. But anyway, I know the gypsum (easily found in the garden section of big box stores as a lawn additive of some sort) is supposed to help keep your colonized grains from clumping together too much. So when you bang your master against the tire, it all comes apart easily for pouring.

So you boil you grainy-mix with a lid until steam shoots out, then lower the heat and boil for at least 30 minutes. It’s to saturate the grains, not to sterilize them. Then you strain it for a few minutes, and I am impatient/busy so I pour my jars immediately with the boiled grains (even though they’re still hot) and then stick them in the freezer for five minutes. By then, they’ve cooled down enough that I’ll pour in “a bit” of my grain master into the next generation jars.

It’s simple really: you want to start with boiled grains filling up around half your fresh jars. Then the more master spawn content (inoculum I think is the “correct term”) you pour into each one, the faster it will colonize. My lids have been punched with four nail holes each and are inverted and screwed on (not too tight). I shake the inoculum up with the new grains, label the date and variety and stick them in a box at room temperature.

Usually it’s looking pretty decently white after 3–4 days, but if you wait a little longer, the colonization will become even denser. I usually end up doing a G2G every 8–9 days or so, depending on the rest of my workload. If you wait too too long or your conditions aren’t good, you may start to see an orange liquid in your jars (this starts more like 2–3 weeks). This isn’t the end of the world, but is a sign to make your transfer relatively soon. Anything green or blue, black or whatever is probably contamination, but I’ve avoided it to so far.

I’ve done this same technique again and again with the oysters and now a couple times off a patch kit I bought for King stropharia/garden giant/wine caps. All totally not sterile, open air, etc. All without any problem. The wine caps I’m using to inoculate a big pile of straw/used poultry litter underneath my hops vines. I don’t know how long that will take, but I have a “good feeling about it.”

Getting the oysters to fruit, of course, is another matter. My G2G tek I could conceivably run all night and all day without problem and end up with hundreds and hundreds of inoculated jars. But after that, I have yet to achieve success.

Here is my “fruiting lab”:

Note how the oat straw is sprouting on the bottom of the “burrito” far right

I know this “looks sketchy” but I can assure you that a whole lot of “high-level science” is being performed here!

The “burrito” on the far right is basically one (or two I can’t remember) spawn jar emptied out into layers of straw, and then folded in a nice chicken wire tortilla. I was watering it occasionally. This room used to be a potato warehouse in a garage and is pretty cool (no idea on actual temp) and shaded. There is natural light, but not direct. I thought it would potentially be a good inoculation area for the straw to get colonized.

If you strip away the outer straw layer a little, you can see the colonization is actually decently underway (though not amazingly so):

Sorry for the bad photo, my “camera is broken”

Anyway, today I moved this guy out of its darkened chamber and hung it up in my greenhouse to hopefully see if some natural light for a few hours in the morning will initiate pinning.

The other two bags hanging are variations on the same concept, but “wrapped in plastic” to quote Twin Peaks. The one on the right has a roll of fencing in it to hold the burrito form, and the one on the left has straw just loose:

Not sketchy!

The bag on the left is “oxo-biodegradable,” a product I picked up at a local pharmacy and investigated a little bit on the web. I’m not sure it’s the answer, but is it better than other forms of plastic? The plastic question continues to vex me, and there appears to be no perfect environmental answer — yet.

If someone wants to make a “disruptive” start-up to “hack” something, why don’t they “hack” plastic bags already? Jesus christ!

The bags have air holes poked all around them. The straw in exactly none of these was sterilized. Neither was it chopped like you’re supposed to do. The blue bag has maybe twice the number of inoculum jars in it. I’m trying sort of a buckshot approach around the best probable answer… See what sticks to the wall.

An old homesteader from way back I stayed with while WWOOFing told me when he starts a new thing, he always gets three books about it by different authors and follows one of the sets of instructions exactly. Then he goes out and tries his own way. That’s probably good advice, but it’s not what I did. I’ve never been one to follow instructions well, but for everything up until the straw phase of the game, I at least tried it the “right way” at first.

Now I’m trying to find out what’s the absolute bare minimum process to follow that will yield a reliable/predictable result. I haven’t found it yet. But tomorrow I’m finally going to bite the bullet, cut up some straw (somehow or another) and pour boiling water over it into a big tote bin and let it soak for an hour.

Because what I’m doing now probably *could* work — eventually. But I want this to all work out sooner than later. Time’s a wastin’ and my season is in full-swing. If I can add oysters (and wine caps) to my existing client offerings, I can stand to profit quite a lot while offering some nice products.

Once I figure it all out, that is! More to follow as it develops —