In Japan, shiitake farmers do not use any agricultural chemicals or fertilizers in the cultivation of natural shiitake mushrooms on logs, from start to end.
Because the pests that eat dried shiitake appear only after drying, there is no need to use chemicals during cultivation.
Furthermore, the shiitake are dried immediately after picking to ensure the shiitake look as good as they taste; so there is no need to use chemicals for retaining freshness.
As the Japanese Chestnut Oak used in cultivation are cut in mountain forests far from other agricultural fields, there are no residual agrarian chemicals detected in the regular monitoring inspections.
Natural log-cultivated dried shiitake in Japan are produced through organic cultivation.
As Japanese shiitake farmers consider the non-use of agricultural chemicals and fertilizers as the norm, they do not leave records that can be used for organic certification.
Natural log-cultivated dried shiitake produced in Japan is all grown without agricultural chemicals and fertilizers.
In Japan obtaining organic certification would not differentiate a product and would have little meaning.
Consequently, Japanese shiitake farmers do not have the motivation to record unneeded entries concerning cultivation and to acquire organic certification.