This is an attempt at a guide for bulking out.
I like starting out with agar in small jars. I usually go spore to agar, agar transfer a time or two to clean cultures. Next I move to grains, and finally coco coir. There's some options along the way of course. Like skipping agar and going straight spore to grain. This works but expect some failed jars. Grain to grain transfers works well to bulk up on grain jars as well.
Starting with agar
I use small masons 125 ml with 2x 3/8 to 1/4 inch holes drilled in the lid. Red hightemp rtv silicone gooped on one, polyfill tightly filled in the other. The red rtv acts as a self heal injection port. Make sure you roughup around the drilled hole so the rtv sticks. Polyfill is for gas exchange (not needed for agar) or air exchange. More on that later.
In a pot I weigh out 16.5 gr agar, 16.5gr light malt extract, 1100ml water, and couple drops food coloring (optional). Once dissolved pour a tiny bit in your jars just enough to fully cover the bottom. Lid up and cover with foil pc for 30 mins at 15 psi. Once cooled they can be injected with a flamed spore syringe, in a glove box. Flame the syringe, prepare to lift the foil, bring the hot syringe in position under the sterile foil, squeeze out a bit to cool it off, then inject a tiny as possible drop.
Once colonised, transfer clean looking wedges to new agar jars via flamed scalpel in a glove box. My donor and recipient jars are lids popped but not open, in my glove box. Donor jar is upside down all work is done with jar upside down. Recipient jar is upright. I flame my scalpel, grab my donor jar cut a triangle wedge while scalpel is hot. Stab the wedge pick it up, set the donor jar down, and gently lift the recipient jar lid and tap the scalpel to drop the wedge.
With healthy agar plates or spore syringes it's time for grain, and quart jars. I use the same modded lids on my quart jars, I upgraded from the silicone and polyfill to synthetic filter disks and be vaccutainer lids.
Most whole grains will work winter rye, whole wheat kernels, whole oats etc.
I am using wheat right now because oats were not available. My pc holds 9 quarts, so I measure out 4.5 quarts of grain. Half dry is a good starting point. Adjust volume next run. I soak my grain over night, boil it in the morning. The soak is important, for endospore germination to be killed during pc cycle.
I boil my grain until it's fairly translucent, easily cut by a fingernail, collapses when squeezed, but not burst. At this point you will have a few burst kernels it's fine. I like to strain mine and lay it all out on paper towel and let it steam dry. It's ready to jar when it no longer sticks to your fingers. It's better the grain be on the dryside than to wet. After jarred and covered lids in foil pc at 15 psi for 1h30 to 1h45. Once cooled inject with spores or agar wedges.
My all or nothing method works extremely well if you can keep good clean plates and sterile technique. Use with caution.
The reason I have an air port on agar is to inject sterile water cooked at 15psi for 45min in a spare quart jar. I then pull this water into a flamed sterile syringe, reflame and inject an agar plate. When I do this I move the syringe in a circle and inject hard to breakup mycelium and draw back up. When this works the jars colonise way faster than the standard wedge shake and wait method. Not for the first timer.
Once fully colonised quart jars are available you again have options. You can shake and break the mycelium up and use some jars to transfer to fresh grain jars to get more spawn. Or move onto coco.
Spawning to coir, the final step aside from picking. Pet store bricks are around 650g, I buy the big 5kg grow blocks and break them up. 650g Of coir is enough to do these 27 quart sterilite clear containers. Doubling it you can squeeze in a 66 quart container.
The formula is a liter water for every 200g coir. So 3.25 liters water for a 650g brick.
Start by measuring the water out in a pot bring to a boil. In a 5 gal bucket with a lid weigh out 650g coco. Place in bucket dump in the boiling water, and put the lid on until cooled.
Now that the coco is ready break up the spawn. I like a wheelbarrow tire for this. Try doing 80 jars hitting your hand, foot, knee etc lol.
When prepping my tubs I drill 2x 7/8 inch holes per side 1 inch above substrate level on the long side, just a few inches from the corner. On the short side 1x 7/8 inch hole an inch or so down from the top in the middle. These holes are stuffed tightly with polyfill while colonising. I cut a trash bag and use as a liner, letting it overhang my tub while I mix up the spawn/coir.
I try to keep a 1.5 to 1 or a 2 to 1 ratio of Coir to spawn. So 2 quart Coir to a quart of spawn. Substrate depth is 4 inches or so. When prepping my tubs I drill 4 7/8 inch holes 1 inch above substrate level
For these small tubs, 3 to 4 quarts of spawn works good. With alcohol wiped gloves place most the coir in the tub save some for a top layer. Next dump your spawn in and mix up real well get it blended evenly. Make it as flat as possible no mountains for a nice even pinset. Place the remaining coir on top covering any exposed grains. Trim the trashbag off at substrate level and put lid on.
While colonising keep an eye out, if you look closely, there are beads of moisture on the mycelium that starts showing. The goal during colonising is to keep it there but not let it develop to huge drops that break and flatten out soaking the mycelium. Adjust polyfill wadding as needed. If drops get to big wipe the sides and lid down.
To trigger fruiting loosen the polyfill, maybe wipe the lid down if its soaked. Sit a fan in the room to create air movement but not directly on the tubs. The goal at this point is to keep a light mist on the mycelium. You may have to spray here and there to maintain a light dew. The evaporation triggers pinning.
After you harvest you can bottom water by pulling trashbag back and dumping water around the substrate. Or dunk your substrate. I like dunking. I use 3/4 inch pex water line cut long enough to go through both sides of the tub. You just poke it though the tub and it holds your substrate down while you submerge in water. The 3/4 pex makes a water tight seal its perfect for the 7/8 hole. I dunk around 20-30 mins, tip to drain water, then flip the tub upside down, and let it drain. The pex holds your substrate in.