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.
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.
1) 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.
This step, and the next one, is where growing mushrooms looks more like a science experiment than farming.
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 hundredd 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.
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.
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).
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.
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).
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?
Another description of the tour
(Cross posted at Ethicurean)
View of the Pacific Ocean from Far West Fungi
Random link from the archive: Local Eating at Culinate
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