Yeah... so I was told mushrooming would be slightly difficult and have a high learning curve. Turns out that the beginning pins stopped their growth.
I've diagnosed it as: half-gallon jars (the same used to feed and colonize spawn) can't be used to fruit mushrooms. The circulation is too poor.
I am going to squeeze the spawn "cake" out of the jars and set them up in a "fruiting chamber". The chamber will be constructed as per my book's instructions. It will require perlite and possibly a little water bubbler, like what you would have in a fish tank (the bubbles keep the air flowing and of a higher humidity).
I'll post as soon as I get it set up.