Maitake

What it is

Maitake is the fruiting body of Grifola frondosa, a polypore that forms a large, branching cluster of fan-shaped caps with small pores underneath rather than gills. It is a perennial that grows at the base of trees, most often old oaks and maples, and often returns to the same place for several years. In English it is called hen-of-the-woods, and in Japanese maitake means dancing mushroom. Other names include sheep's head and ram's head.

The cluster is made of many thin caps joined at a common base. Cooks tear it into pieces by hand rather than cutting it, because the caps separate along their natural lines. The species was first described as Boletus frondosus by Dickson in 1785, and it is placed in Grifola by Gray in 1821.

Where it grows and where it is eaten

The wild species occurs in China, Europe and North America. It is most common in eastern North America and has been found as far west as Idaho. Fruiting in Europe runs from August to October, and in eastern North America from September to October. It has been eaten for centuries in China and Japan, where it appears in nabemono hotpots, tempura, takikomi gohan (mixed rice), and soba.

The young caps are the most prized. The softer caps must be cooked thoroughly, and the mushroom can be pickled. Some people are allergic to it.

How it came into cultivation

Japan was among the first countries to cultivate maitake artificially, starting in the mid-1980s. Researchers in the 1970s had worked on growing it at scale on logs and sawdust substrates. In the 1980s indoor techniques allowed temperature, humidity and carbon dioxide to be controlled closely. Bag culture on a sawdust-based substrate is now the most common method in Japan, mainly because it is cheap and the indoor environment is easy to control. The sources do not give yields, cycle lengths or substrate recipes, so this page does not give them.

The same encyclopedia entry places wild and cultivated maitake under the category of fungi in cultivation, and cultivated maitake is now widely sold. The catalogue record for the species describes it as widely cultivated.

Flavour and how it cooks

Maitake tastes sweet and savoury. The encyclopedia entry attributes this to its trehalose, to glutamic and aspartic acids, and to 5'-nucleotides. Those are the compounds that give the mushroom its depth in broth and in fried dishes. The softened caps need longer cooking, and the firm inner parts stay textured after frying.

In Japanese cooking the clusters are added to rice dishes, simmered in hotpots, dipped in tempura batter and added to soba. The clusters hold their shape well in broth, which is why they suit nabemono and slow-simmered dishes.

Health claims and what the evidence supports

Maitake is widely promoted for health. Its antitumour activity was first reported in the 1980s from hot-water extracts of the fruiting body, and later research has focused on its polysaccharides. The Wikipedia article reports that no high-quality clinical evidence supports medicinal use, and that as of 2019 no completed high-quality Phase III trials existed. A 2009 study found a sulfated polysaccharide from the species could act as an immunomodulator in breast cancer survivors, and its authors noted the whole mushroom may not produce the same effect. This page treats those claims as preliminary.

Notes and open questions

The Wikipedia article gives no cultivation history section, so the Japanese dates here come from the encyclopedia entry. The catalogue treats the scientific name as a research label rather than a settled name. The sources do not give a shelf life or a drying method, so this page gives none.