You can store unknitted spawn at about 65 to 70 degrees F in a moist environment for a few weeks, to see if it will turn white, or you can return it and ask for your money back or a white bag of spawn. If you receive your spawn more than a few days before you plan to inoculate, you should place it in the refrigerator or a very cool basement. Move spawn to room temperature about 24 hours before you plan to inoculate. When ordering a preinoculated log or sawdust block, make sure you tell the supplier the fruiting temperature conditions, so you will get the right inoculated strain. The three types of trees most often used for production of shiitake mushrooms are white oak, red oak, and sweetgum.
White oaks are the most productive and are bothered the least by invasions of foreign or weed fungi.
But, white oaks require the most patience, since it usually takes 8 to 12 months from inoculation before the mushrooms first begin to fruit. Red oak and sweetgum have softer wood and will produce mushrooms in 6 to 8 months. They also require more careful management since they are more susceptible to other fungi, bark peeling, and rapid water loss. Shiitake mushrooms will also grow on American hophornbeam, ironwood, laurel oak, cherry, sassafras, sycamore, tulip poplar, and hickory. How well the shiitake mushrooms grow on logs from these trees depends on how much care you give the logs and how well you control moisture, temperature, and exposure to other fungi.