the point is that each kernel should be completely or nearly completely colonized.
Before being exposed to air. Mycelium of this type is very highly resistant to contamination and it grows very quickly.
In order to eliminate using tyvek or other filters we just use the air in the jar.
When Mycelium runs out of oxygen it goes into stasis which of course can be revived by more oxygen.
The Mycelium should cover most of the grain before being exposed or you will get contamination. Most often at this stage you will get a bacterial contamination that will fool a newbie into thinking there is no problem but the Mycelium will stall. If shaken, the Mycelium will spring back.
What happened in your case is as you suspected, simply was not enough air inin your jar to sustain growth for just long enough to cover every piece of corn.
To every one else, one of the problems with pf tek is that you have to wait so long for the cake to grow out, and you usually waste nutrient while you wait.
The point here is that given environmental temperatures of 80 or should never take more than ten days total.
Your grain cost what? Five bucks?
Your enthusiasm is worth more and this method always yields something new to look at.
Get the right jars, fill them half way or a little more and try again.
If you are short on spores, consider that you can sterilize water, let it cool and draw it into a partly used syringe.
Or even an empty one if you had preserved it.
