dry out since water will be lost as vapor under any conditions and these are just the most exposed grains. To solve this, we have just been folding the top part of the spawn bags over the filter patch to essentially block and slow down some of that gas exchange from occurring. Also having less air in the top of the bag helps to fold over and prevents having a large area where gas exchange constantly takes place. I am not the best versed in understanding CO2 relations during the spawn run but Erik should see this and be able to chime in or expand on some parts. I will also ask the great Tyler Crawford and see if he mentions anything different.

So we keep our spawn room around 700-800 ppm CO2. The concentration inside of the bag will be much higher than the outside which is ideal during the spawn run. This mimics nature where the mycelium is spreading underground and will have limited gas exchange. Different filter patches have different air exchange rates, we are using a 3B unicorn filter patch for our spawn bags. In terms of thermodynamics the main heat exchange is going on between surface of the bag and the outside, the filter patch won't have a huge impact on this flow of heat. The main heat is coming from internally of the bag from the fungi metabolism so keeping some space between bags helps them not to keep bouncing heat off of each other. Our spawn room stays at 65-70 and this maintains the bag in about the mid 70's range. You are spot on with the grain drying on the top surface. So we had this problem as well and it is due to the air exchange with the filter. The more gas exchange then the quicker that the grain will

Tyler Yes, we have been dropping agar into brown rice bags and also some oat.  We use 2 cuttings of agar (about a 1 cm square) per bag for our grain masters (4lbs) and then spawn across the usual 12. The yellow bits you are seeing won't be the agar but rather the metabolites being produced by cordyceps. The rice gets these very yellow and some orange bits that grow around the edges of the grain and throughout the bag.

Phillipe Kenny sounds about right, definitely thinking in the right directions!

2nd and 3rd does indeed look like stroma. That yellow discoloration followed by a hard mass are the defining signs that we look out for on our end. Although the first video shared makes me think a little more along the overlay way of things as it seemed still fairly white and not like one hard tumor. The warming up of the incubation space and letting the mycelium hang out for too long are factors that increase the chance of stroma and overlay. In our experience we only see stroma form on the surface of the block and not internally, but when going to spawn just be observant when breaking up the block and keeping an eye out for these yellow hard masses throughout the bag. We have tossed the spawn if stroma is noticed, but if low on inventory we have removed the pieces of stroma when opening the bags to spawn with. Saying that though if there is stroma the size that you are encountering, we just toss the bag, as at that stage it's just too far gone in the direction of stroma.

Never forget CoW are also referred to as the Sulphur shelf mushroom and can get a very pungent rotten egg smell when cultivated. This is just the mushroom being itself and should be nothing to be worried about as your plates showed. I'm guessing it's stronger with bag cultivation indoors as the air isn't always in motion and there is a strong collection of uninterrupted mycelium constantly creating these metabolites.

Look at all those fun shingles, I got to clone a wild species a couple months ago and we are still in trials but who knows it become a commercial strain! Awesome to see others out there making it work.

David Medlock We have grown on both MYA and PDYA and noticed no significant differences, maybe just a slight variation in growth time. Also online it seems people switch between both, I'm guessing from their own preference but nothing set in stone. We don't use peptone for our plates but there was an article in which they used peptone as part of their supplementation mixture that got added to the substrate. It showed an increase in fruit body yield and cordycepin production when getting to fruit body stage. So, I don't think it would necessarily be a bad idea as it seems the cordyceps utilizes the peptones.

Appreciate it, thank you for the good vibes🤘