Hey folks. Here is a detailed description of the method I use to grow P. cubensis. I have had very good success and have worked out most of the bugs so this method is guaranteed to produce lots of our little, happy friends. Unfortunately for most of you, I have access to laboratory equipment including an autoclave (for sterilization) and an incubator (for growing at constant temperatures) but I think you can substitue your own homemade stuff like a pressure cooker.
I start with P. cubensis mycelium which has been grown on an agar plate. The agar media I use is Potato dextrose agar (PDA) from Difco. This contains Potato dextrose broth and regualar agar at 1.5 g/L. I am sure Malt extract agar would be just as good or even some home made version of PDA. The agar was autoclaved at 121 C, 15 psi for 30 min and was then cooled to 50 C. At this temperature, the agar was aseptically poured into petri plates and allowed to cool and solidify. These plates can now be stored in a plastic bag in a cool location for as long as you want. If there was any contamination, it should show up after about 3-4 days at room temperature. If there is none, then the plates are good to use.
The P. cubensis strain I use was obtained from a local store and I was assured that it was a good one. Basically, the strain is dikaryotic and can be used directly to inoculate jars. I first aseptically transferred a small piece of mycelium containing agar to a few plates and grew them at 30 C for 1 week. Two of these plates were set aside as my stock cultures so that I did not have to go back to the original (and risk contamination) and were stored at 4 C (in the fridge) with some plastic wrap around them to keep in the moisture. They were also stored upside down so that any condensed water would collect on the lid and not on the surface of the agar. The other plate was used to inoculate a bunch of new plates with small pieces of mycelium containing agar. These new plates were grown at 30 C for one week. After this time, a nice white, kite string-like mycelium had grown. The kite string-like mycelium was actually only found in sectors on the plate and it was these areas that were used to inoculate jars of rye substrate.
Rye substrate was prepared using 130 g of rye seed combined with 100 mL's of water in a 500 mL (pint) jar. The jars I used had plastic screw-top lids which could be left partially unscrewed to allow air to enter. Also, mineral suplements like CaCO3 could be added to the water but this was not found to be necessary. Once the rye and water was combined in the jar, the jars were autoclaved at 121 C, 15 psi for 1 hour. These were then allowed to cool to room temperature with the lids partially unscrewed in a sterile area overnight. The next day, two small pieces of mycelium containing agar (from a kite string-like sector), aproximately 0.5 cm by 0.5 cm in size, were added to each jar aseptically and the jars were shaken. These jars were then incubated at 30 C in the dark for 2 weeks with shaking every 3-4 days to evenly distribute the mycelium. It is crucial that the lids of the jars be very loose at this stage so that air can get in to the growing mycelium.
After 2 weeks of incubation and occasional shaking, the jars of rye were
found to be fully colonized with white mycelium.
These trays of cased substrate should now be incubated in a humid environment, in the dark at 24-30 C for about 3-5 days. The trays can be kept moist by gentle misting with water at this time. Too much water is not good so don't overspray. During this time, I keep my trays in a plastic tent with no extra humidification. The tent is basically a small wooden shelving unit from IKEA which has been covered with clear plastic. Alot of water collects on the lids of the tray and this indicates that a very nice humid environment exists inside. Remember, at this stage nohumidification is required. Don't over water. After 3-5 days, white mycelium should be poking up through the vermiculite casing.
Once quite a bit of mycelium has poked up, but not too much, the temperature should be lowered to 20-24 C and the trays should be exposed to regular bursts of sunlight (i.e. open the curtains). At this time, mistings should be ended and the inside of the tent should be kept very humid using a humidifier. Be careful because over humidification can be a problem. This should continue for about 2 weeks. Small shrooms begin to appear in about 1 week and continue to grow over the remaining week.
That's about it. Happy growing.