In a world first, a Japanese research institute has developed a process for making sake from trees, with at least one startup aiming to commercialize its cedar-based product by 2025.

The Forestry and Forest Products Research Institute devised the manufacturing process, which is similar to that for producing shochu, to create unique flavors using cutting-edge fermentation technology, considered to be the first of its kind in the world.

Although the high cost of installing equipment for the production process presents a challenge for companies wishing to enter the market, the research institute is focusing on lending its support for commercial production to increase demand for domestic timber.

In late July, Kyodo News was given access to the facility, located northeast of Tokyo, to taste Japanese white birch, cedar, Lindera umbellata (used in high-grade toothpicks) and Mongolian oak samples. The clear liquid had a fresh wood aroma, with the alcohol content adjusted for tasting at 25 percent.

Samples of distilled spirits made by the Forestry and Forest Products Research Institute -- (from L) Japanese cedar, Mongolian oak, Japanese white birch, and Lindera umbellata -- are pictured in Tsukuba, Ibaraki Prefecture, in August 2023. (Kyodo)

The birch sample had an aged taste, much like whiskey, while the Lindera had a fruity, sweet aroma.

The sake contains ingredients typically found in a variety of beverages and foods, such as wine and loquat orange. Even when freshly made, the sake has complex flavors and deep aromas, as though it has been aged for a long time in a cask.

Ethical Spirits, a venture company based in Tokyo that makes sake from discarded sake lees, or leftover sake residue, is aiming to commercialize its product. The company has received training from the research institute and has mastered the fermentation technique.

According to Yuichiro Otsuka, 46, a senior researcher at the institute, until now, the sugar contained in the trees used to initiate the alcohol fermentation process could not be extracted without the use of strong chemicals, which made it impossible to produce alcohol safe for drinking.

Yuichiro Otsuka, a senior researcher at the Forestry and Forest Products Research Institute, shows a block of wood and a bottle of tree-based sake in Tsukuba, Ibaraki Prefecture, in July 2023. (Kyodo)

But in the wake of the 2011 accident at the Fukushima Daiichi nuclear power plant triggered by an earthquake and tsunami, a non-chemical fermentation method during the process of attempting to produce methane gas from biomass, including wood that contains radioactive substances, was found.

The institute then discovered that the method could be used to produce alcohol safe for human consumption and set about exploring its potential for commercialization.

Through the newly discovered "wet-milling" production method, the sake is made by pulverizing wood to less than a thousandth of a millimeter, which releases natural sugars.

The wood is mixed with water to break it down into mash using industrial equipment refitted for the purpose, and sugar created by adding enzymes to the microparticles is fermented with yeast and distilled. Developed in 2018, the technology was patented by the institute in 2021.

A machine specially designed to produce the sake can make about 750 milliliters of distilled liquor, equivalent to a bottle of whiskey, from cedar weighing about 2 kilograms. By installing a larger machine, firms will likely be able to produce at least 50 bottles per week.

Equipment for pulverizing wood into mash is pictured at the Forestry and Forest Products Research Institute in Tsukuba, Ibaraki Prefecture, in August 2023. (Kyodo)
Wood in a mashed state after being mixed with water and pulverized at the Forestry and Forest Products Research Institute in Tsukuba, Ibaraki Prefecture, is pictured in August 2023. (Kyodo)

"We can also utilize unused timber left over from forest thinning (chopping down trees in dense forest areas)," said Kazuya Tatsumi, 26, who is in charge of the project at Ethical Spirits, adding that the company aims to market its wood spirit brand made from cedar in Saitama Prefecture, outside Tokyo, by 2025.

The research institute says that if domestic businesses with brewing licenses use domestic timber, they will be allowed to use the patented technology, and new market entrants will be offered training in a dedicated research building.

But so far, only four companies and organizations, including Ethical Spirits, have signed contracts, with the cost of the equipment, estimated at 200 to 300 million yen ($1.3 to $2 million) being a key issue.

Given there are about 1,200 species of tree in Japan, however, a variety of tree-based sake flavors are possible, according to Otsuka.

"If we can take advantage of subsidies from the national and local governments, we can open the way to the realization of this project...We would like to create new value for timber with people who are interested in this project," Otsuka said.

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