Fortunately, if you have access to oak logs, you can grow them outdoors yourself. Inoculated logs will fruit for years every fall, but usually need 16-18 months after inoculation for fruiting to commence.
Maitake is a weak competitor. Like growing Shiitake or Oyster mushrooms on wood logs, you will inoculate the logs with spawn, but we highly recommended that you pre-treat the log first, then bury the log outdoors and let the fall weather bring on the fruiting. A prep/planting schedule looks like this:
Late fall through early spring → cut oak logs
March through April → pre-treat logs and inoculate
Through June → incubate logs indoors
By end of June → bury logs outdoors
Fall, up to 18 months after burial → fruiting
What is "pre-treatment"?
Wood logs come with their own protective bark sleeve which is sufficient to hold in moisture and prevent invasion of other fungi, allowing for fast colonization of whichever spawn you plant into the log. With Maitake, however, spawn run is unreliable but we can help it along by pre-treating the log in one of three ways: sterilizing it in a pressure cooker, boiling it for 1 hour or steaming it for 6 hours.
Which method is best?
Pressure cooking gives us the highest rate of colonization, but it requires a big enough cooker to hold a 2 lb. log, which we believe is the minimum size for good sized clusters and long term fruiting. Your pressure canner should be a minimum size of 12 qts, and you can process a bigger log if you have a 23 qt size canner. Not comfortable with (or don't have) a pressure canner? The next best choice would be to steam or boil the log prior to inoculation. These each can result in a higher contamination rate in the finished log, but if carefully done and inoculated in a quiet, clean area of your house, can be very successful. You will need a large stock pot for either method. Boiling is a little more uncomfortable to work with, as the log must be boiled for one hour and taken out of hot water when time is up. Steaming (just as you would vegetables, rack on the bottom, a few inches of water and lid on) takes 6 hours, but the log can cool in the clean pot awaiting inoculation. We recommend using large autoclavable bags that will hold up to the heat with all three methods, but these are essential for the pressure cook method. If you have a large cooker you can pre-treat lots of logs, just like we did in the new FFP sterilizer (see below)!
After a few months incubation, locate a burial spot for your log in a well drained area with partial to full shade. Dig a hole the size of the log and place the log in the hole (you can bury the log vertically or horizontally). Cover the top of the log with a dusting to 1/2 inch of soil. It's also a good idea to mulch the area with a thin layer of wood chips or straw to keep developing mushrooms free from splashing soil as they develop in the fall. Make sure to stake or flag where your log is buried. Ours have been lost under the hostas!
Growing Maitake this way may seem putzy, but it is the most sure fire and economical way to get Maitake, unless you are lucky enough to know where your wild Maitake trees/stumps are hiding. If you are "stumped" for good Maitake recipes, use them where you can showcase their crunch and distinctive flavor. Roasting on a sheet pan, they can be used in every way possible.