After sufficient incubation your fully myceliated grain is now ready for inoculating a suitable growing substrate or for exponential expansion of your stock of cultured grain. There are two things to bear in mind before getting too excited about the idea of exponential expansion. Firstly, each generation of grain transfer increases the risk of contamination. Secondly, each generation will affect the vitality of the mycelium as a process of senescence creeps in. So it’s best to limit yourself to three generations at the very most from your 1st generation mother spawn.
Grain transfer are ideally carried out in front of a HEPA filter laminar flow hood. If you don’t have this then a “glove box” will suffice along with a very stringent decontamination regime before the transfer.