Reishi is prepared in many different forms. Until the last few decades, it was only available as a wild mushroom. Now cultivated varieties are common, with some more potent than their wild counterparts.
Because reishi mushrooms have a hard chitinous shell that is indigestible, it must be processed in some way so we can absorb its medicinal compounds.
- Hot-Water Extraction
The most common and traditional way to prepare reishi is by hot water extraction. This method is what has been done for centuries of use in Traditional Chinese Medicine and other ancient practices, so its health benefits and safety are the most recognized. Reishi can be steeped in hot water for at least four hours. Then the liquid is filtered, and the solids are discarded. This process can be repeated. The resulting liquid can be consumed as a strong tea that can also be used as a base for making soups, broths, or sauces.
For supplements, the water portion is often removed with a spray dryer to leave a concentrated powder that can be consumed in powder or capsule format or bound into tablet form.
- Pulverized / Micronized
In this method, the reishi is prepared by pulverizing the fruiting body into a powder to be encapsulated or used as a tea. However, as reishi contains chitin, a fibrous indigestible polysaccaride that forms its hard outer shell, pulverization methods do not yield any absorbable compounds without extraction.
- Alcohol Extraction / Dual Extraction*
Another way to turn a reishi mushroom into a supplement is by using alcohol extraction (ethanol) or dual extraction (ethanol + hot water). This method is done to extract more compounds from the mushrooms. The alcohol is then evaporated, leaving behind an extract that is thick and concentrated. Alcohol extract can be made into capsules, tablets, tinctures, powders, and tea bags.
*While there is some benefit to using dual extraction to more efficiently extract water-insoluble components of reishi (ie. such as triterpenes) with alcohol/ethanol as solvents, there is also the risk of introducing unknown and toxic substances including solvent residues into the final product.
Reishi has traditionally been extracted using water only which has been time-tested to be safe through centuries of use in Eastern Medicine. Modern highly pressurized hot water extraction methods can still extract triterpenes such as Ganoderic Acid A (and the water-soluble components (ie. beta-glucans) without the added risks of alcohol toxicity.
A simple test to determine the quality of a reishi product is to taste it. Reishi has a distinct, earthy and bitter taste and is prevalent in sources that contain pure reishi essence.