The mushroom line-up to the right was sourced from a local supermarket in Scarborough for the price of $2.38 CAD.
With the exception of the older mushroom, second from the left, each had its outer surface cut away. This left me with four solid pieces of mushroom in rectangular box shapes.
I then sliced off 3 or 4 thin sections from the top of each and let them soak in a relatively strong hydrogen peroxide (HP) solution for about 5 minutes. A 3% HP solution was mixed with water in an approximate ratio of 1:5.
You can see the mushroom pieces foaming to the right. The HP is reacting with the mushroom pieces, and any other organic material, and releasing oxygen. Other than being interesting to watch, the reaction is killing off competing mold and fungus spores and bacteria. To ensure the death of all competitors, the mushroom pieces were occasionally stirred around.
The cardboard was sourced for free from the liquor store; not the corrugated cardboard the boxes are made from, but the non-coated insert that is used to keep the bottles from clanging together.
Note of interest: Here in Ontario liquor can only be purchased from the provincially owned liquor stores.
The cardboard was cut into rectangles approx. 1" by 3" and also soaked in the HP solution for about 5 minutes.
The 1 litre jar to the right was cleaned and then it, and the plastic wrap, were sprayed with a 99% solution of Isopropyl alcohol. I'm sure a 99% solution is over-kill, but I have a large container of it.
The jar and its contents are now sitting quietly in a dark cupboard. I will check in on them in a couple of days.