Channeling Energy

After ruminating about the sterilization process and ensuring that the reason for suboptimal yields in not the substrate sterilization, I am realizing that there is another possible reason for my reduced yields - the pinning process.

So I'm staring at my lions mane blocks and realizing that the blocks I've been top-fruiting, which have now been switched to side fruits after the first flush, and I see that the mushrooms are not forming where the cuts have been made. Well let's back up a little and let me explain more.

There are two main methods of fruiting mushrooms from plastic bags (either 10-lb or 6-lb). They can be top fruited or they can be side fruited. Top fruiting usually promotes faster growth as the entire top of the block is exposed to the fresh air and humidity. However the mushrooms are typically smaller as there are a large number of smaller pins. With side fruiting, a smaller surface area is exposed to the air through cuts of varying sizes dependent on the growers preferences. Some sort of X cut or U cut is typical. This is usually the preferred method as mushrooms grow of the side of trees and so this mimics their natural habitat more so than top-fruiting. Additionally, the side-fruiting usually creates a smaller number of larger and more dense mushrooms which is more desirable from an aesthetic perspective. See diagram below.

Top-fruiting vs side-fruiting

Top-fruiting usually creates a faster first flush as mycelial growth condenses towards the top as that is the side which is exposed to the sealed bag's micro-patch filter, which allows for small amounts of fresh air exchange. The implication is that the concentration of nutrients will be higher on the topside of the block, allowing the mycelium to pin faster when exposing that side of the block to fresh air.

In contrast, the side-fruiting method does not have that advantage. While I am not certain of this, my suspicion is that when the mushrooms are side-fruited, the mycelium must expend a small amount of energy moving the nutrients (as concentrated slightly more at the top) and then also around the bag, to the opening where the cut is made. This accumulation of nutrients then allows for the pinning process to occur. Usually, the pinning process takes about 3 - 4 days, so this is how long it takes for the mycelium to "get ready."

To take advantage of a faster first flush then also the benefits of side fruiting, some growers like to top-fruit for the first batch, then side-fruit for the second. I have done this with some success with the yellow oyster which start creating large primordial bases from which the mushrooms will shoot-off as soon as conditions become more favorable. If the bag is not top-fruited after the pins have formed at the top, then they are essentially wasted and the mycelium has used - maybe 5 - 10%? - of its energy in vain, obviously contingent on how long the pins have become. Therefore, the timing of when the bags are moved from the colonization stage to the fruiting room is critical.

This groundwork leads me to my realization. After top-fruiting the lions mane, then transitioning to side-fruiting, I did not adequately fold up the top such that there were no bits of mycelium exposed to the air (only new cut for the side fruit should be exposed). This caused a huge problem where the mycelium attempted to fruit from two essentially opposite sides of the block at once. This in turn, causes the mushrooms in both locations to be smaller than they otherwise would have been, as the mycelium sent nutrients to both openings.

So in conclusion, the lesson is that where the bag is exposed to fresh oxygen and humidity is extremely important as that will trigger pinning. If pins form in undesirable locations where it will not lead to quality mushroom growth, the resources have been wasted and this will reduce total yields by up to 20 - 30%. It is possible that this issue in tandem with under-sterilization was the main reason for my reduced yields. Looking back, I did not always move the mycelial blocks from the colonization room to the fruiting room, likely resulting in a suboptimal pinning process.