Japanese Sake Breweries Enter Digital Age With Production Aid; Optimizes Timing of Key Process Steps

At Mizutani Shuzo, a sake brewery in Aichi Prefecture that dates back to the late Edo period, Miwa Goto opens a spreadsheet on her computer and enters the alcohol content of the fermented mixture, the amount of water added and other data.

A graph will immediately appear showing the progress of the fermentation process.

Mizutani Shuzo is one of a growing number of sake breweries using a digital tool developed by the Nagoya Regional Taxation Bureau that automatically calculates the degree of fermentation of sake and presents the data in graph form.

The tool, called “Moromi-eru” — for “moromi,” the fermented mash at the heart of the process, and “eru,” to encourage or support — uses digital technology to help brewery workers who, for centuries, have had to rely on rules of thumb or individual instincts. The aim is to help breweries maintain quality and preserve sake culture.

Japanese sake is made by making moromi from rice, koji mold, and water, and then pressing out the liquid. The fermentation process can be modified by the amount of water added, temperature, and other factors, and the timing of the pressing affects the final product.

Each sake brewery keeps a daily log of added water and other data. By entering the numbers into the digital tool, the degree of fermentation can be automatically calculated and displayed in a graph. This serves as a visual aid to decide when to press the moromi, removing the need for personal instinct.

For reference, the tool also shows the fermentation rate of previous gold award winners at the annual Japan Sake Awards.

The brewery in Mizutani Shuzo, located in the city of Aisai, was hit by a devastating fire in May of this year, completely destroying the building and destroying most of the brewing logs.

This season, the company plans to resume operations by leasing space from another brewery. In preparation, it is entering data that was not lost in the fire into the digital tool.

“It will make it easier to reproduce the sake we used to make,” said Goto, 26.

The digital tool made its full debut in January last year. According to the tax bureau, it has been provided to at least 40 sake breweries in the Tokai region, and others in the Tohoku region and elsewhere have expressed interest.

At the Fukui Syuzo brewery in Toyohashi, Aichi Prefecture, the tool has helped shorten working hours.

“The tool’s data on the degree of fermentation supports my own instincts based on my experience, making it easier to determine when to press,” said a 67-year-old sake brewer.

Shortage of brewers

In Japan, the administration of alcoholic beverages is handled by the National Tax Agency. According to statistics from the National Tax Agency, the number of sake breweries in the country has decreased by about 40% in the past 30 years, and the consumption of seishu (refined sake) has decreased by 70% during that period.

This trend can be attributed to the popularity of cheaper alcoholic beverages such as beer and beer-like products, but also to the aging of the brewmasters (tojis) and the inability to find successors to run the breweries.

The Nagoya Tax Bureau hopes that the tool will help monitor sake production and maintain quality to a certain extent. This will lead to improved operational efficiency and a solution to the labor shortage.

“The individual instincts and experience of the toji are of course important,” said Kenichiro Tajima, head of the bureau’s Office of Analysis and Brewing Technology. “The tool helps produce a stable supply of good sake. Sake is going to make a comeback.”