A forest research institute in Tsukuba, Ibaraki Prefecture, has succeeded in making “wood sake” by developing a technology that produces alcohol suitable for drinking by fermenting wood through a method used to produce sake.
According to the Forestry and Forest Products Research Institute, the method is the world’s first of its kind. It is also possible to give the resulting alcoholic drink a flavor like whiskey.
“We are looking forward to commercializing this ‘wood sake,’ so that the usage of wood will be expanded,” an official of the institute said.
Alcoholic fermentation of wood also occurs when producing biofuels. However, in that case, wood materials need to be processed with sulfuric acid or at high temperatures to dissolve the cellulose — plant fibers — from which alcohol is produced. The process makes the alcohol unsuitable for drinking, as it contains harmful substances.
The institute developed the technology to crushing wood into infinitesimal chips — one micro- meter, or one-1,000th of a millimeter, in diameter — by churning wood with a large number of tiny metal balls in water.
This enables yeast and enzymes to dissolve cellulose without processing the wood at high temperature, thus finishing the fermentation process without losing the aroma of the wood.
The institute obtained a license to test-produce alcoholic drinks from the National Tax Agency, and tried “brewing” alcohol using various plants, such as cherry trees, cedar and white birch. The experiments were able to produce liquids having aromas like sakuramochi confections or flavors like whiskey aged in wooden barrels.
The institute will confirm the products’ safety and other aspects of the drink and aims to commercialize the products within three years. It hopes that the “wood sake” will push demand for domestically grown wood in the future.
Kengo Magara, a researcher responsible for the development project, said: “In Japan, there are about 1,200 species of trees. I hope people will be able to enjoy alcoholic drinks made from trees peculiar to each region.”