Attention!

The documents In this archive are meant for historical research purposes only. To find updated PF Tek information and procedures please refer to the Getting started > PF Tek and General Cultivation links provided under the mushroom info tab of your home screen.

Psilocybe cubensis mycelium has an ideal growth temperature at 86?F and a "thermal death temperature" at 106?F. (TMC). Which means it literally dies at 106?F. But once the colonizing jars reach higher temperatures, the mycelia will eventually slow growing and halt for 2 main reasons. As it approaches thermal death, it is less and less likely to continue to grow effectively. Further, higher temperatures will almost always lead to a drying out of the substrate. When substrate becomes dry, mycelia will stop growing (since it needs water to propagate). Also, dry substrate becomes impenetrable for mycelia - as PF substrate becomes hard and brittle when dry. Your best bet is to keep it as close to 80?F (warm but not hot) as possible, and fluctuate only as necessary. The temperature inside the jars is always a few degrees above the outside temperature since the mycelium generates heat while colonizing the substrate. Note the sharp drop of growth as temperatures become increasingly hot in this diagram. Since the reduction in growth drops so sharply at 86 degrees, it is best to keep temperatures lower to avoid the risk of exceeding the maximum point of return illustrated above.