Reishi mushroom is a wood-decay fungus that grows on both hardwoods and softwoods, often on stumps or fallen trees, but also at the base of living trees. Some species of Ganoderma, the common genus, can be found mostly in temperate climates. It has also been successfully cultivated in many countries around the world.
Different species of reishi grow naturally in different areas of the world. Ganoderma lingzhi (red reishi) grows wild only in East Asia. Ganoderma lucidum is more commonly found in Asia and Europe, while Ganoderma tsugae is more widely available across North America.
Types of Cultivation
Reishi is a mushroom that has been sought after for centuries. In China, red reishi was once reserved for use by royalty, such was its value. Since its medicinal value is well-known and documented, many people have tested ways to best cultivate it, and each cultivation method produces a slightly different product. The type of reishi you need depends on what you plan to use it for.
Here’s a look at the three major methods used to grow this popular medicinal mushroom.
Natural Wood Log Cultivation:
This is generally considered the best method to use when cultivating red reishi mushrooms. It provides the largest possible amount of fruiting body without having to sacrifice quality or size. First developed by the Japanese, the first step is to culture a high-quality reishi strain for about 85 days in a test tube. These germinating fungi are then put into drilled holes in a high-grade log. The logs can be produced from various hardwood trees, including maple and oak, among others. The key is to find logs with a high sugar content, which will allow them to produce mushrooms for several years. They should also be free from disease and mold. The logs are then buried under nutrient-rich soil in a greenhouse where they are kept under specific growing conditions for about five months.
Wood Pulp Cultivation Method:
This is a method of growing the mushroom in an enriched sawdust and wood chip substrate. The method can be used to grow a number of different types of gourmet mushrooms and has been used extensively to produce shiitake mushrooms in particular.
Wood Box Cultivation:
The most common method for growing reishi mushrooms is a wood box cultivation. This is an artificial log that is used to grow reishi mushrooms in. You can buy these from online stores or make one on your own by drilling holes into the log and inserting dowels.
Reishi Parts that are Cultivated
Mycelium is the network of thread-like structures called hyphae, from which mushrooms grow. In the case of reishi mushrooms, the part that you normally associate with the mushroom is the stem and cap, and it is the fruiting body of the mycelium. The mycelium is like the roots of the reishi mushroom.
Reishi mycelium is typically grown on a solid grain spawn medium in a sterilized laboratory environment. The grain spawn is mixed with a liquid culture, and the reishi mycelium is allowed to grow throughout the media.
The reishi mycelium is then put into large tank vessels, where it is allowed to continue to grow and reproduce within the substrate. Once the substrate has been fully colonized by the reishi mycelium, it is ready for extraction. Mycelium is not what has been used for thousands of years by traditional medicinal practices and it does not contain all of the beneficial medicinal compounds of the whole mushroom.
Broken/Cracked Reishi Spores
Once a reishi mushroom fruiting body matures, it releases spores from the underside of the head. These spores can cover the mushroom and the micro-environment in just hours.
The spores are especially rich in triterpenes—more ganoderic acids and oils—making it more potent in this regard than the fruiting body. The fruiting body will be higher in polysaccharides and beta-glucans.
Since humans cannot digest the spores as is, they must be “cracked” or “broken” using modern methods to allow us access to the valuable compounds inside the spores. Because of this extra step, the cracked spores are often more expensive to purchase than reishi itself.
Broken, cracked, or otherwise damaged reishi spores can be cultivated in a number of ways. One way is to take the broken reishi spores and place them in a glass jar. Then, fill the jar with water, seal with a lid, and allow it to sit for three weeks at room temperature before harvesting. The glass jar should be glazed and ideally placed in indirect sunlight.
The other method involves taking the broken reishi spores and placing them into a glass container, with the lid closed. No water is added to the container. Instead, the spores are left to sit in the glass container filled with air for three weeks before harvesting. The glass container should be placed on top of a heat source and kept at 43°C (110° F) for optimal results.
Reishi Spore Oil
Once the reishi spores have been cracked, spore oil can be extracted. This oil is a potent source of some of the reishi compounds, particularly the triterpenes.
The fruiting body of reishi is the most valuable part for acquiring most of the medicinal compounds of this fungi, so the cultivation of the fruiting body has usually been the focus of research.
The fruiting body of the medicinal mushroom red reishi is cultivated by placing mycelium spawn into a growth medium as mentioned above (natural wood log, wood pulp, or wood box) and incubating them.
At least two weeks of incubation are needed to allow primordia formation. The primordia will begin to appear as small white bumps on the inoculated substrate, which will eventually grow into fruiting bodies.