All-in-one Myco Bags

All-in-one Myco Bags

Here’s an elegant tek I learned from the Radical Mycology book (credit goes to Peter McCoy). When prepping bags for wood lovers (Hericium erinaceus in this case), embed a disk of cooked wheat grain into the bulk substrate (could be sawdust / hemp hurds / coir etc.) and then sterilize. Once cooled, inject liquid culture (mycelium) through the bag and onto the grain disk. Incubate the bags and let the mycelium grow through the grain. Once fully myceliated, break up the grain disk and mix the contents of the bag. Each myceliated kernel then serves as a leap-off point for the mycelium to rip through the bulk substrate. Genius.

So simple, so beautiful! No need to run grain in separate jars and then transfer the contents to the bag. No need for a flowhood or difficult grain-to-bulk transfers in a still-air box. Less waste, fewer contamination vectors, less washing up.

Photos to Illustrate

A top-view of the grain disk / puck. In this case, the bulk substrate is hemp hurds and coco coir supplemented with gypsum and wheat bran.

The mycelium has now completely engulfed the grain and begun venturing out into the bulk substrate. The added benefit of this is that the mycelium is now aware of the constituents of the bulk substrate and has activated appropriate enzyme-production pathways. This means there is barely any lag-time when the grain disk is broken up and the individuals kernels are separated.

Notice that the bag has not been filled to capacity. Achieving even distribution of the grain kernels is very difficult when the bag is too full. Don’t be greedy when filling the bags; you will be thankful for the extra space and will achieve quicker and more-complete myceliation if the grain is evenly distributed.

The Results


Pseudoranty addendum:

I will say this again and again: you do not need a flowhood to achieve your wildest myco-dreams. Other ways are possible! Cultivators who are proficient in no-flowhood techniques are far more resilient than those who have been spoiled by HEPA :wink:


This is brilliantly genius, i love it! @glyph
Thank you for sharing this

When you eventually mixed up your grain disk (after colonization), did you open or keep your grow bag closed to do so?

Those Lions Mane are quite the sight to behold. Amazing

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When you eventually mixed up your grain disk (after colonization), did you open or keep your grow bag closed to do so?

The bag is sealed before sterilization and stays closed the entire time. With Hericium erinaceus in particular, it’s import to squeeze all the air out of the bag before fruiting begins (otherwise fruitbodies will form inside the bag and not at the slits / holes where we want them to).

If the cultivator doesn’t have an impulse sealer to seal the bags, they can use a piece of metal wire (like a twisty-tie) or a plastic zip-tie* to seal the bag prior to the pressure cooker run. The seal can be completed by wrapping a piece of parafilm over the bag opening once the bags come out of the pressure cooker.

* We want to keep single-use plastic to a minimum, so metal wire is preferred over zip-ties.