Well, the jars have cooled and the mycelium transferred to the jars of substrate.

I sprayed a 1.3% solution of hydrogen peroxide (H2O2) inside the top portion of the jars and on the inside of the lids before placing the pieces of mycelium on the cardboard tops. The mycelium pieces were then given their own light spray of 1.34% H2O2. I am concerned that my H2O2 solution is too strong.

I filled the top 1" space of two jars with vermiculite that I had soaked in a 0.5 % solution of H2O2. The vermiculite will act as a barrier to airborne contaminants, but allow the transfer of gases. I am leaving the top layer of vermiculite out of the third jar to see what happens.

The lids were secured. The two with the vermiculite barrier were then topped with plastic screening; the same you may have in your screen door at home. With any luck the screening will keep the fungus gnats out of my jars. The one jar with without a vermiculite barrier was topped with its aluminum foil cover and the screening.

I left a couple of mycelium pieces in the original jar with two more strips of cardboard and a light spraying of 1.3% H2O2. The cardboard had been soaked for 5 min. in the 0.5% H2O2.

Now to wait and see.