so i made a huge batch of bulk substrate and ill have alot leftover, if i bag it and steam cook it, can i freeze it to keep it preserved till im ready to use it again?

also one other thing, when i fruit, do you think a dark dingy basement would hold enough humidity for the mushrooms? it smells musty down there and its always damp, u think i should still build some kind of humidifer to put into the plastic bin that im fruiting in?