If we simply lay more substrate on colonized substrate all we get are delays and possible contamination.
And no signal.
A true casing layer (the term is badly misused, I have even seen the term "casings" as though that means anything at all. They may even be perverting "castings" which is worm excrement.
It is absolutely true that cubensis does not need to be cased. HOWEVER, as we discussed earlier, bare colonized substrates just don't absorb water. The organism needs lots of it. The primary limit to fruiting is moisture and your mycelium will never exhaust all of your substrates nutrient. It will run out of water before it alters the ph to the point where that substrate is inhospitable.
So, the most effective way to supply water to the whole system is to have a nice, thick, sparsely colonized layer of fluffy, spongy casing with an initially high ph value.
This casing layer is also highly conducive to being colonized by beneficial bacteria which will (no studies have been done for this species but others show compelling results), support denser flushes.
As I said, no casing is needed but if one wishes to orchestrate a succession of thick, lush flushes then casing is pivotal.
Furthermore, one can more easily alter ph using casing than using substrate.
We want our substrate to be smack dab in the center of optimal ph in order to have the organism grow strong and rapidly. Then we can introduce a lopsided ph casing that is heavily buffered to absorb the acid metabolic juices the mycelium expels. When there is a huge mass of powerful mycelium underlying a less than ideal casing environment then it just doesn't matter, those little knots will set up shop anyway..and they are more likely to be profuse.
We are now far less susceptible to our arch enemy, trich which all but refuses to grow in alkaline environments.
And we can easily bring that layer up to maximum water capacity. No "dunking" necessary.
There is another way, the use of "water crystals" when assembling our substrate.
The crystals leave the substrate open and airy while it is being invaded and steadily releases water directly to the mycelium as the substrate otherwise becomes exhausted of water.
While this seems to have no effect on the first flush, subsequent flushes are far larger and more flushes are common.
Curiously, after what I have said about casing, the addition of water crystals (balls to be exact, tge crushed ones don't work), placing them in substrate seems to do nothing at all.
