How to Grow Shiitake Mushrooms

Out of all the classes we attended at the Mother Earth News Fair, this had to be one of my favorites.  I've been thinking about growing mushrooms for the past several months, not only because Hubs is a fanatical mushroom lover, but because it's my dream to be in business for myself so I can quit my job and focus on my family.  I had been doing some research and found that I could set up my own mushroom "farm" in our basement to grow mushrooms such as morels, oysters, and "buttons."  I hadn't gotten around to researching shiitake mushrooms yet, so I really wanted to attend this class.  I'm really glad I did--the instructor was informative, energized, and pretty darn hilarious.  I expected the class to be taught by some vegan hippie, only to find a guy in his mid-fifties, non-vegan, and who had a personality somewhat like my dad's was.  He was very matter-of-fact about how dicey mushroom farming can be, but he also talked about how much fun it could be.  So, here's what I learned about shiitake mushrooms and mushroom farming:

Shiitake mushrooms originated in Japan.  The word "Shiitake" comes from two Japanese words:  "Shii" = oak tree and "take" = mushroom.  So, literally, shiitake are "oak mushrooms," named for the type of tree the mushrooms grow on in Japan.    I lived in Japan for 3.5 years so I knew "take" means mushroom, but I didn't know about the "shii" part. You learn something new every day!

Shiitake are not only delicious, but they also have many different uses.  According to ShiitakeMushroomLog.com, "Shiitakes are high in protein, vitamins, and minerals. Fresh and dried shiitake mushrooms are used nutritionally to fight cancer, fibrocystic breast disease, high blood pressure, and viruses, and to help strengthen the immune system, improve circulation, and reduce cholesterol."  Now, I don't claim to be a doctor or health professional so take this info with a grain of salt.  I did a little research and found that shiitake mushrooms ARE used as an anti-cancer treatment so perhaps there is something to it.  I just like how they taste!

Shiitake mushrooms growing on a log

Basically, shiitake mushrooms are grown on oak logs.  But, according to our instructor, you can also use elm, pin oaks, sweet gum, yellow hornbeam, hard poplar, white ash, beech, sycamore, willows, and aspen logs.  You have to cut your logs in the cooler months (October-March) so any spore from other mushrooms can die off and won't interfere with your shiitake spore.  Logs should be about 3-4 feet long and about 6" in diameter--basically big enough to grow mushrooms, but not so big that you can't pick them up and carry them.  You want to choose logs that have medium density bark so your mushrooms can grow easily on them but other fungi/bacteria can't.  Also, about two to three weeks before you are ready to get started growing mushrooms on your logs, you need to either soak them in non-chlorinated water overnight or douse them really well with a garden hose a couple of times a week before you start the growing process.  This will ensure your logs have enough moisture content to support growing mushrooms.  You must not use chlorinated water or it will kill your mushroom spores! 

Our instructor recommended ordering our shiitake spore from a company called Field & Forest. www.fieldforest.net  I've checked them out and they seem to be reasonably priced.  Our instructor has worked with them for years and swears by them. Basically, the process of "seeding" your logs with mushroom spores is called "inoculating" your logs.  Usually you want to do your inoculation in the spring, when the weather starts warming up, usually after your last frost.  Temps should definitely be above freezing before you try this.  Inoculation occurs when you've drilled holes in your log and you plug the holes with the mushroom spores.  Holes should be drilled about 6" apart and to a depth of about 3/4" to 1 and 1/4" inch deep.  Our instructor has a drill with a bit in it that has a "stop" in it for 7/16."  He says it's a lot easier than trying to measure.  Here is a photo of a mushroom log drilled filled with plugs:

Basically, to inoculate your logs, you plug the spore into each hole, hammer it in until it is flush with the surface of the log, and then seal it with either a wooden dowel (as seen in above photo) or you seal the holes with wax, using a small paintbrush to apply the wax.  Our instructor swears by using beeswax (natural, no chemicals, etc) and since we have bees making beeswax right at this moment, that's probably what we'll use, too.  After your logs are plugged with your mushroom spore, you want to find a spot in your yard that is semi-shady and unlikely to be disturbed by kids or pets.  The instructor leans his logs up against his split rail fence under a grove of pine trees.  He recommends putting the logs under pines because they have less of a chance of contracting foreign fungi than if you stuck them under hardwood trees.

If you tend to live in a dry area, you'll want to make sure you water your logs regularly so the mushrooms can grow well.  Another thing I didn't know about growing mushrooms was that they are technical called a "fruit."  So when you force mushrooms to grow on a log, you are "fruiting" your logs. 

Apparently, shiitake need to be "shocked" into fruiting.  In Japan, the logs typically start fruiting after an earthquake or a heavy thunderstorm.  Since we don't normally have earthquakes here, (okay, that one last month was a complete fluke!) our instructor recommends "thumping" the logs--basically holding the log up and down (like a post-hole digger) and thumping the end on the ground.  He showed us a photo of a little experiment he did in which he set a group of logs aside, and out of that group, he thumped only half of the logs.  Sure enough, mushrooms only grew on the logs that he had thumped.  Interesting!

Other websites say you need to shock your logs into fruiting by soaking them in water that is 20 degrees cooler than the air temperature.  Some recommend sticking your logs in the fridge or freezer for 24 hours to force them to fruit.  Apparently, the colder the log gets, the more mushrooms you get.  Sounds kind of brutal to me, I'll probably stick with the thumping!

Once you've found a spot for your logs, you need to water them every once in awhile so they don't dry out.  The log is basically food for your mushrooms and the longer you can keep it around, the more mushrooms you'll get.  Some logs last up to 4-5 years with multiple "crops."  It may take up to a year and a half after you inoculate your logs with mushroom spores for you to actually harvest any mushrooms, it just depends on your climate, log choice, etc.  In the wintertime, depending on your climate, you may want to cover your logs with straw or hay; do not use plastic tarps--they encourage mold growth.

So, in a nutshell, here's a quick and dirty description of the process.  Cut your logs, order your spore, soak your logs, drill your logs, plug your logs with mushroom spore, seal the plugs with beeswax and put your logs in a shady part of your yard that still gets some light.  Water and thump them regularly to encourage fruiting.  You should see mushrooms in anywhere from 9 months to a year and a half.  Good luck!

Shiitake Mushroom Recipe:

Shiitake Mushroom and Cheddar Soup, serves 8

Ingredients:

• 4 slices bacon, chopped
• 1/2 white onion, chopped
• 1 pound shiitake mushrooms, sliced
• 2 cloves garlic, minced
• black pepper to taste
• 2 leaves fresh sage, chopped
• 6 cups beef broth
• 1 cup shredded Cheddar cheese

Directions:

1. Place the bacon in a large saucepan, and cook over medium-high heat, stirring occasionally until crisp, about 5 minutes. Stir the onion into the pan; cook until soft, about 5 minutes. Stir in the mushrooms, garlic, pepper, and sage; cook over medium heat until the mushrooms begin to brown, about 10 minutes.
2. Pour in broth; bring to simmer. Simmer soup for 10 minutes. Reduce heat to low, sprinkle in Cheddar cheese; stir until melted.  You can garnish the soup with sliced shiitakes for presentation if you like.

Our instructor says that he prefers to dry his mushrooms and rehydrate them when he needs them.  He said a lot of people dismiss the stems as being too tough but he's figured out a way to use the stems, too.  He dries the stems, then uses his food processor to make a powder out of the stems.  He then adds cream, and garlic to make a cream sauce for anything from lasagna to lobster.

Another website recommended by our instructor is Fungi Perfecti http://www.fungi.com/  I just went there and found out that the wacky-looking mushrooms on my front lawn are called "Turkey Tail" mushrooms.  I guess they do sort of look like a male turkey's plumage.  I also found out through my research that the Asian markets love to buy shiitake that have been been "frostbit."  Apparently, they think it makes the mushrooms taste better and that they are more potent than regular shiitake mushrooms. 

Finally, I thought this quote from our instructor was quite funny:  "All mushrooms are edible; some only once." --Old Croatian saying