Author’s note: I am not a biology or mycology expert, so please forgive any small discrepancies in this article. To learn more about mycology from people who actually know what they’re talking about, visit the Mycological Society of San Francisco or the Mycological Society of America.
When you buy your mushrooms at the market, you may think that they are all foraged in the woods. And while this might be true for some varieties, most mushrooms customers buy are actually grown on mushroom farms. Mushroom farms!
Last month I got to tour Far West Fungi’s Moss Landing location and learn all about inoculation. Far West Fungi is a long-term member of the Ferry Plaza Farmers Market, and also has a permanent storefront inside the Ferry Building. Customers can buy chanterelles, truffles, portabellas, oysters, buttons, and more, as well as a variety of truffle oils, dried mushrooms, truffle salts and mushroom powders. They do work with some foragers for products like chanterelles, but grow most of their mushroom varieties at their cultivation farm.
Far West grows mushrooms that would naturally grow on trees in nature, so they are basically trying to re-create a natural process. They use sawdust, a medium perfect for growing mycelium, mostly red oak and cherry sawdust. Because sawdust has small particles, it provides more opportunities for the mycelium to inoculate and grow. Far West Fungi goes through a pile once every two weeks.
The sawdust is mixed with organic rice bran, which provides sugars and proteins for the organisms that produce mushrooms. They separate the sawdust mixture into polypropeline bags lines with a resin and a micron filter patch to make sure spores can’t get contaminate the mixture. Each bag is called a block. They heat each block to 254 degrees for 3.5 hours in order to kill all contaminants.
Each block is then sprinkles with about a teaspoon of the organism, in a room that pushes the air in one direction and the workers shower and wear suits before entering to prevent contamination. Then the blocks go into incubation rooms, where the airflow and temperature is controlled.
All the blocks Far West Fungi produces go into the same incubation rooms for four weeks, where the organism grows through the block. The oyster mushrooms are ready after four weeks, but others like the King Trumpets need a few more weeks, while the shitakes need an extra nine weeks (oyster mushrooms are the easiest, and will grow on basically any carbon source). These are moved to separate inoculation rooms that have dripping water to keep the humidity up.
The mushrooms are the fruiting body of the mycelium, and fruit when the bags are split and the mushrooms have enough time to grow.
Many mushroom farms are in the area, because the coastal climate is perfect for mushroom cultivation. That being said, Pennsylvania is actually the biggest producer of mushrooms.