A fun day with some fungi

I went on a CUESA-organized farm tour last Sunday to Monterey County, about 2 hours south of San Francisco (Jen Maiser was also on the tour and wrote about it at Bay Area Bites). Our first stop was Far West Fungi in Moss Landing, just a few miles from the Pacific Ocean. The Moss Landing area is close to Salinas, the lettuce bowl of America, and is a mix of moderately-sized industrial farmland–monocultures stretching across wide swaths of land; strawberries here, brussels sprouts there, lettuce over there–and smaller operations like Far West Fungi and our second stop, Yrena farm (which I will write about another week).

Far West Fungi sells their mushrooms at several farmers markets in the San Francisco area and has a shop in the San Francisco Ferry Building marketplace.

Upon disembarking from the bus, "farm" was not the first thought that popped into my head. "Abandoned military base" or "the set of a grade-B horror movie" ("Hey everybody! Let’s all go play spin the bottle in that creaky building with the red splotches on the door!") seemed like better descriptions. But the facility does what it needs to do–provide temperature and humidity control–as the high quality of the Far West’s product illustrates.

Our tour guides were John and Toby Garrone, the current owners of the company. Although John has a long history in the food business, he got into mushrooms almost by accident. While working as a police dispatcher in San Francisco in the 1980s, John met someone who was starting a mushroom farm in southeast San Francisco, near the Hunters Point Naval Shipyard.

Making mushrooms

Growing mushrooms is a multi-step process, with plenty of waiting between some of the steps. I’ll go through the process, as explained to us on the tour, most likely missing some details here and there.

sawdust pile1) Preparing the growing medium
One of the most important raw materials for mushroom cultivation is a growing medium. Far West Fungi is certified organic, so they have strict requirements for their material. They are fortunate to have an agreement with a nearby cabinet and door maker who supplies red oak sawdust (in huge quantities, as the photo to the left illustrates). After arrival on site, the dust ages for 12 weeks to make a suitable bed for the mushroom culture (something happens as it ages to make it "right"). The final growing medium is a mixture of the aged saw dust, oyster shells (or another source of calcium) and rice bran. On a normal day, the company’s workers fill about 3000 gallon-sized plastic bags per day.

After filling a bag with the growing medium, it is placed on a cart, which is then rolled over to the sterilization area.

2) Sterilizing
This step, and the next one, is where growing mushrooms looks more like a science experiment than farming.

Mushroom autoclave

The cart from step 1 is rolled into a large autoclave that has a door on each side (photo right). After a period of heating and cooling, the cart is wheeled though the door on the other side to the "clean room."

3) Starting the culture
The fungal culture is grown on a petri dish in the clean room. When the culture is mature, it is divided among ten 2-liter-sized flasks that are filled with the growing medium. These flasks remain in the clean room while the mycellium (the "roots" of the fungus) grows to fill the flask. Next, the flask’s contents are divided among one hundred bags filled with growing medium. When the bag contents are mature, the contents of each bag are split between ten bags. Thus, one petri dish ends up supplying life to 10,000 bags.

4) Incubating
The bags go through two stages of incubation, each about 30 days long (shiitake, however, need 60 days of secondary incubation). During these two periods, the mycellium digests the growing medium and fills all available space, turning the color of the bag contents turn from a deep brown to nearly pure white.


The initial incubation room


5) Growing
After incubation, the bags are moved to the growing rooms. The wood-digesting mushrooms grown by Far West Fungi need light, so a few fluorescent lamps are always turned on. They also need moisture, resulting in periodic blasts of water mist.

At this stage, the bags are finally opened up–either with one end sliced open or with a small plastic collar installed around a hole in the bag (the collar directs the growth of the mushrooms into a cluster that is more easily harvested and more attractive).

6) Harvesting
Once a day, harvesters walk though the growing rooms to cut off bunches that are ready for sale. The mycellium in each bag goes through one "fruiting" before it runs out of growing power.

7) Cleaning up
Once the harvest is complete, the growers are left with a plastic bag filled with mycellium, the remnants of oyster shells, rice bran and sawdust. This material is sent to a nearby compost company to be converted to fertilizer (which is especially good for orchards, according to John Garrone).

Oyster mushrooms in a growing room

A selection of mushrooms: top row, maitake and yellow oyster; middle row, tree oyster and scarlet oyster; bottom row, lion’s mane (a.k.a. bear’s head) and shiitake.


A few final notes

One of the things I realized during the tour is that Far West Fungi’s facilities don’t need to be in such a rural area. I noticed few, if any, unpleasant odors (the shiitake growing room had a rather pleasant aroma). It was hard to judge how much noise the facility makes, however, because the sterilization machine was not running (it’s powered by a steam boiler, which probably makes all kinds of hissing noises). Therefore, it is conceivable that a parking garage, or office building, or even a grocery store could be built with a mushroom-growing facility underneath. Has such siting been attempted anywhere? Or have mushroom farms been located within a lumber processing facility (which would have plenty of pure sawdust and excess steam to run the sterilizing machines)?


View of the Pacific Ocean from Far West Fungi


(Cross posted at Mental Masala)

4 Responsesto “A fun day with some fungi”

  1. Anonymous says:

    I wonder, is this the common process for mushroom farms? That seems to be an awful lot of plastic bags being used.

  2. Yes, it is a lot of plastic bags. I don’t know whether other growers of oyster, shiitake and other tree-based mushrooms manage their crop the same way.

    As far as I know, button mushrooms (i.e., “normal” mushrooms in white and brown hues) are typically grown in open horizontal beds instead of on vertical racks, so there is no need for the plastic bags.

  3. dorotan vasile says:

    My name is Dorotan Vasile and i would like to relate you that after i’ve been our country escaped from the communism
    i’ve been tried an individual business: the culture of Pleurotus.Whitouth any help of money from the bank
    (which has 120% profit) i built an underground cellar of 4/50m…in 15 years i still cant’t tell that i advanced very much…
    i had problems in everithing….ventilation,compost,cutting machine…mycelium…but i resolved them whit my own forces
    and whith what i had.For example the mycelium is created by me from grain whit fire under a cask isolated with brick.
    Please tell me how do I work with fresh beech sawdust, send me pictures and tell me how mutch should I steam it.
    And if you want to see in what beautiful place I leav please visit my site http://www.canyonlapus.piczo.com!

  4. Jeff says:

    Yes, the bags are necessary and is the norm for the type of mushrooms grown (wood lovers). The inside of the bag must remain sterile while the mycelium is colonizing the bag. The bag has a built in filter to allow air exchange without contaminants getting in. The other practiced way to grow mushrooms of this type is to inoculate logs with the mycelium. This way however takes entire seasons if not several years to produce the first mushrooms where as a bag will produce mushrooms in just a few weeks. Logs if they produce will do so for years if they do not dry out. But as you cannot look inside the logs, you cannot tell if the log is being colonized or not. All in all, bags allow the grower to produce large amounts of mushrooms in a short time using minimal space.