Hey Marcin,

Thanks man. Yeah I'm pumped for how things are going to be building out from here.

I am completely on board for open automated myco-machinery. So much potential as there are a variety of machines used in Asia for small to industrial operations that are just not available in the states. I'm sure many would be relatively simple to open source, but I am no engineer...

For straw.. I would forego the ferment and opt for lime treatment, which I believe I mentioned at the last greenhouse workshop. Rather than waiting 2 weeks, you soak in high pH (~12) water for 16 hours and drain. It's quicker and tends to yield better than fermented straw. Plus the water can be reused and doesn't smell horrible.

I would love to see a machine that you could throw a whole bale into to have it shredded into small (~1-2" long) particles that are spit directly into the soak tank. This could be any size drum. My friend just showed me his $1,500 bale shredder (does a whole bale in 5 minutes) and old fuel tank (approx 100 gallon size) that he had on its side, with an axle welded through the center that rotated via a motor and chain outside the drum. The axle had holes drilled so water or steam (his treatment menthod) is pumped into the drum filled with chopped straw. The drum was powdered coated inside to keep it clean and "fins" made of angle iron were welded inside to encourage mixing as it turns. Of course, I have been excitedly waiting for the final prototype of your soil mixer to play with similar means – in my case, mixing sawdust and other ingredients (a different approach to growing).

Whatever the vessel, the lid would be sealed, and lime water would fill it up. After 12-16 hours, the water drains into a second holding tank for later reuse and the straw is left to sit until it stops dripping. Grain spawn is added at the appropriate ratio, the drum tumbles to mix in the grains, then the mix goes down a hopper and is dosed into clean, drilled buckets. Having another machine that cleans the buckets would be huge. Like industrial dish washers in restaurants, but bigger.

What you described sounds feasible as well. It would be nice to pre-mix the grain spawn to get it uniformly dispersed in the treated straw before loading the buckets. This would reduce labor and the risk of contamination from the cultivator's hands.

If you want to just fruit a bucket or two per week, the shredded straw could be spit into clean, non-drilled 5-gallon buckets and stacked. Shred one bale every three months to prep ~12 buckets (one each week for 3 months). Then each week one bucket would get filled with lime water to soak, then drained the next day (the buckets could, say, have drain spigots in them), and then transferred into a clean drilled-out bucket as it's inoculated. Grain spawn jars can also be pre-sterilzed in advance. So spend one day every 3-6 months sterilizing a bunch of grain jars. Then each week inoculate one or two with liquid mycelium stored in the fridge (the grains can be in the closet, etc). These grains would then be ready 2-3 weeks later. That way pressure cooker work is kept to a minimum. Of course, folks could also just order grain spawn. This is just one possible route of countless others.

Someone from the OSE workshop actually reached out last year interested in a similar idea, but then disappeared. Here is a write up I sent him that summarizes my thoughts on the idea of (much needed) automated mycology:

Spawn Creation

Background:

Decomposer (saprobic) mushroom mycelium grows best on organic wastes that have been shred to create a high surface area, hydrated, heat treated (either sterilization or pasteurization, depending on the materials, species, and technique), packed into an appropriate container (i.e. something that retains moisture, provides filtered [to 0.02µm] gas exchange, and is clean).

There are 3 common systems employed commercially to achieve these goals:

For some easy-to-grow commercial species (e.g. Oyster mushrooms), straw or other ag waste is shredded with machinery, simultaneously hydrated and treated either in a hot water bath, a high-pH bath, or in a 7-day fermentation process. The straw is then drained, inoculated, then placed into a container (either a plastic column with holes poked in it, or a bucket with holes drilled in it). This is the process I taught in part at OSE.
Other commercial species grow best on sawdust that has been supplemented with materials that are more prone to contamination and thus need to be sterilized. These materials are shredded and mixed by machinery, hydrated manually to desired levels (typically determined by feel, but this can be quantified), mixed into mushroom grow bags, sealed with an impulse sealer, and sterilized with a (pressurized or non-pressurized) home-built or commercial autoclave, cooled, then inoculated under controlled conditions (i.e. in a lab). This is the system most commonly employed by growers in the states and around the world. It is very labor intensive as most steps are done manually. Here is a video of an automated system in Asia.
Similar to option 2, but the materials are not placed in bags but reusable polypropylene bottles with removable lids that host an air filter. Fully automated systems can been designed to mix the materials, load the jars into rack. Once loaded, the racks are usually wheeled into a large autoclave to be sterilized, and once cooled, machine inoculate them by quickly opening the lids to introduce mycelium. The racks are then placed into an incubation space. Once in place, these systems are said to be the most efficient, but one of the biggest time sinks can be cleaning the containers/bottles. Great videos on this can be seen here, here, here, and here.

After inoculation, the containers are then set in a 55-70ºF space for 2 weeks-3 months (depending on several variables), until the mycelium has run through the material.

The inoculum is produced separately and is a process in its own right. To start, I suggest we assume the grower will buy spawn from an outside source.

Here are some links to large scale machinery to get any ideas flowing: 1, 2, 3, 4.

Goal:

In essence, I think our primary goal should be to translate the automated liquid-inoculated bottle systems used industrially in Asia into a system more approachable for the small, medium, and larger grower in the states. The videos linked under number 3 I think could give a good idea of how this could look. This would be the game changer in the states and is really the best approach to mushroom growing.

Specifically, building a substrate mixer, bottle filler/tamper, liquid inoculator, scraper, and bottle cleaner.

Figuring out a reliable and cost-effective way to make a pressure cooker from a propane tank or something like it would also be huge for growers.

Alternately, an even simpler goal would be to create a low-labor system for option 1 as this is largely a manual process as well. This is a good option too as it would make Oyster growing easier and more time efficient. These are the species most commonly grown in the world after Buttons/Portobellos.

Fruiting

Background:

As described in the videos, after the mycelium runs through its substrate, the container is opened and the environmental conditions are changed. Temp is often dropped, but the most important things are that the O2 is increased significantly and humidity is raised. It needs to be around 90% rh for a few days to initiate mushroom formation, then dropped to ~80-85% for maturation. Some farms use two rooms for each humidity level and roll carts between the rooms. Or the humidifier settings can be changed manually or via automation.

Goal:

A well-designed and easily scalable automated fruiting environment would be amazing. There is little standardization between grow rooms among small-medium scale growers, just a lot of piecing together whatever humidifers and hygrometers and/or humidistats one can get/afford. The videos above show whole warehouses dedicated to fruiting. The scale down is a greenhouse (sunk in the ground would be great to keep temps low) or even a plastic-wrapped indoor greenhouse in an area with the appropriate temperature. Here are links to some rough arduino-based builds: here and here. Making an open-source hydration system based on this would also be amazing.

Once we dial that in, the next phase would be making the inputs and outputs more and more closed loop. Mushrooms take in wastes and create an array of value added products beyond mushrooms. For example, the left overs after one species is grown can be used to grow others, or make into a plant fertilizer, or used in a biodigester. Lots of options like this as well.

Yep yep!

Peter