Exposing the cakes or casings to cold temperatures for around 24 hours is supposed to trigger pinning.
Exposing spawn or casings to cold temperatures for around 24 hours is supposed to trigger pinning. This is not necessary for Psilocybe cubensis because it is a tropical species. Other edibles may benefit or even require cold shocking. Please refer to the growth parameters of your species. It seems to be beneficial with some strains which don't form pins easily. Make sure that you wrap the spawn well before putting it into the fridge, since the fridge is often not the cleanest place in terms of mushroom cultivation.
Cubensis eats substrate best at around 82F. Although this is the optimal temperature for cubensis it's normally best to incubate cubensis at room temperature around 70-75F because the higher the temperatures the bigger the chances of competitor molds getting a foothold. The further you drop the temperature, the SLOWER mycelium will digest nutrition. it may even STOP growing all together.