The Mushroom Farm

This real mushroom farm, Earth Angel in Pacific, shipping 400 or more pounds of mushrooms daily, is an old warehouse with four rooms: the first one for starting oyster and shiitake mushrooms from clones, using slices of mushroom, because spores won't work for commercial growing -- in a sterilized "clean room" in sterilized growing media: sterilized compressed blocks of sawdust pellets or sterilized cottonseed hulls in a plastic bag. Then the bags are shelved in a room kept at around 70 degrees to encourage mycelium, or threads of pre-mushroom, to grow. In the photo you can see mycelium, the brown stuff, at its most developed in the bags on the top shelf, while the other bags are in process. It has to be organized.

In the cold-and-humid room, ceiling pipes dripping chilly condensation, the mycelia bear fruit: oyster and shiitake mushrooms. Shiitakes are on shelving. Standing in columns are the oyster mushrooms, pictured, growing out of pinpricks in the bags, multiplying dementedly. Imagine a 20x40-foot room full of mushrooms.
They're harvested here. The fourth room is for packaging.

How to learn to grow mushrooms on this scale? The owner cheerfully answered, "Failure." Any grower must experiment dozens or even hundreds of times and waste tons of materials before he gets mushrooms -- shiitakes, especially, are very difficult to grow. I personally asked him, "Do you like cooking and eating mushrooms?" He said yes, but if he had a pound of mushrooms he'd rather sell them than eat them. This eye-opening tour was arranged by the Missouri Mycological Society.