My first attempts to harvest spores unfortunately failed, as the hats all started to mold beforehand, I had several attempts running in parallel. I paid meticulous attention to cleanliness, i.e. with washed hands, inside a transparent box from the DIY store where I cut holes to get my hands in (improvised Stilair box), and the lids on the jars were covered with fresh aluminum foil over the separated mushroom heads, and the cutting tool was heated with a flame and cleaned with isopopanol. - I still have a grow kit here which is about to be harvested, so new opened caps will soon be available to start further trials.
something went wrong on the first attempt.
So, if possible, you need to use caps that are already wide open and may have already started to sprout, and it is important with the spore lid method that the jars are in a dry place while the caps are under the aluminum foil on the lid of the jar so that the accumulated moisture is applied as well as possible.
You always have contamination in the air, unless you have a real sterile box or an airflow bench. If moisture from the hat is added, it can start to mold in 2-3 days. But if it is sprouting quickly, then 1-2 days are easily enough to inoculate the substrate in the glass!
In my current experiment, the hats were placed on the perforated lid on a glass with nutrient solution, so the moisture of the nutrient solution is also added. If I don't add nutrient solution but substrate, I also have a certain amount of moisture from the substrate - because it also has a certain amount of moisture. Both variants have to do with moisture per se. Hmmmh ....