The shiitake mushroom, also known as Chinese black mushroom or black forest mushroom, is an edible mushroom typically cultivated on the shii tree. Two Chinese variant names for high grades of shiitake are dōnggū ("winter mushroom") and huāgū ("flower mushroom," which has a flower-like cracking pattern on the mushroom's upper surface); both are produced at colder temperatures.
This mushroom is native to China, and has been cultivated for over 1000 years. The first written record of shiitake cultivation comes from writings during the Sung Dynasty (960-1127 CE), but some documents record this strongly flavoured gourmet mushroom was being eaten in 199 CE.
In China, shiitake has a history that dates back to the Ming Dynasty (1368-1644 AD). The mushroom was used not only as a food but was taken as a remedy for upper respiratory diseases, poor blood circulation, liver trouble, exhaustion and weakness, and to boost chi, or life energy. It was also believed to prevent premature aging.
Shiitake have many uses in Chinese and Japanese cuisines. They are served in miso soup, used as the basis for a kind of vegetarian dashi, and also as an ingredient in many steamed and simmered dishes.
Shiitake are often dried and sold as preserved food in packages. These must be rehydrated by soaking in water before using. Many people prefer dried shiitake to fresh, considering that the sun-drying process draws out the superior umami flavour from the dried mushrooms by breaking down proteins into amino acids. The stems of shiitake are rarely used in Japanese cuisine. The stems are also rarely used in other cuisines, primarily because the stems are harder and take longer to cook than the soft fleshy caps.
Today, shiitake mushrooms have become popular in many other countries as well. Russia produces and also consumes large amounts of them, mostly sold pickled; and the shiitake is slowly making its way into western cuisine as well. There is a global industry in shiitake production, with local farms in most western countries in addition to large scale importation from China, Japan and elsewhere.
Shiitake mushrooms have been researched for their medicinal benefits, most notably their anti-tumor properties in laboratory mice. These studies, the earliest dating back to 1969, have also identified the polysaccharide lentinan, a (1-3) β-D-glucan, as the active compound responsible for the anti-tumor effects. Extracts from shiitake mushrooms have also been researched for many other immunological benefits, ranging from anti-viral properties to possible treatments for severe allergies.