The Ultimate Food: How to Grow Mushrooms

Imagine a food that is low in fat and calories, but is rich in vitamin B and C and has more protein than any other food. Imagine this food can reduce cholesterol, inhibit tumors, and benefit the immune system. This miracle food is also relatively quick and easy to cultivate-even indoors. For these reasons, the culinary and medicinal properties of mushrooms have been enjoyed throughout history from the early Greeks, Aztecs, Mayans, and Japanese to modern cultures.

Since their early use, mushrooms have been studied enough to develop simple and reliable cultivation techniques. Many types of mushrooms can be propagated in the appropriate settings by growing mycelia, or live fungus tissue, in a nutritious substrate, using the fungus to inoculate less nutritious substrate, adding a thin layer of a moist, non-nutritious substance, and harvesting the mushrooms that sprout. The first step is to obtain spores or a culture of the species one wants to cultivate.

Mushrooms reproduce through spores or live fungus. Therefore, in order to grow mushrooms, one needs to either find or buy live mushrooms or spores. Many online stores exist that sell spore prints, spore syringes, and live tissue cultures. Spores can even be obtained from free spore rings that will mail out free spores if the recipient pays for the shipping costs.

Once the spores have been obtained, they can be used to grow fungus in a nutritious substrate. There are many different substrates to choose from. Most grains, like brown rice and millet, can be ground into flour and mixed with vermiculite and water and put in a jar, forming a substrate cake. Although grains can be used whole to make a better substrate, they are harder to sterilize than flour. If whole grains are used, they should be soaked for 12 hours and rinsed under a faucet prior to sterilization. Once the grains are soaked and rinsed or the flour is mixed with water and vermiculite, they are packed into jars with a small hole in each lid to allow steam to escape and gasses to exchange.

The methods used to sterilize the substrate depend on the type of substrate used. Flours can be sterilized by placing the jars in a pot of lightly boiling water for an hour and letting them cool slowly. This technique, called steam sterilization, can be adapted to sterilize whole grains, but it is significantly easier to pressure cook the jars for an hour at 15 psi.
Once the contaminants have been removed from the substrate through sterilization, it can be inoculated by mixing spores or tissue into the grains or flour. Spores and tissue can either be injected or manually scraped onto the substrate. Hopefully, only the desired fungus will grow on this nutritious substance. In order to speed up the colonization of the substrate, the jars should be incubated at temperatures in the high eighties.

The jars of substrate should be completely colonized within a few weeks. At this time, the substrate may be spread into cake pans or similarly sized trays. The deeper the layer of substrate, the more mushrooms will grow. If substrate cakes were used, they can be crumbled and spread like colonized grains.

A casing layer can be applied to these trays. The casing layer is a layer of a non-nutritious, moist, porous substance on top of the trays which gives the fungus more water to produce mushrooms with and protects the substrate from contaminants. Many mushroom growers use peat moss, limestone, and water. Whatever formula is used, the casing layer must be sterilized. It can steam sterilized or microwaved for approximately ten minutes. The casing layer should be one to three inches thick and should be applied evenly but roughly.
The cased trays can finally be fruited in an airtight container. The chamber must be humidified by adding a one to three inch layer of moist perlite to the bottom, with an aquarium bubbler and a cup of water, or many other suitable methods. Some types of mushrooms need light to initiate mushroom production, but any type of light can be used.

Within weeks, mushrooms will have formed. To harvest these fruit bodies, grasp them at the base and carefully twist while pulling. This will leave a small divot. To prevent contamination, these holes should be patched with sterilized casing material; this way, more flushes of mushrooms will be able to form.

It can be very satisfying enjoying the fruits of mushroom cultivation. These benefits can be had by using spores to inoculate substrate, using this substrate to inoculate a fruiting substrate, adding a casing layer, and fruiting in a humid environment. Mushroom cultivation can be a practical and enjoyable hobby; after all, who wouldn’t want to be able to eat nature’s perfect food all the time?