TSUNAN SAKE BREWERY Speaks to Kansai Sake Brewing Engineers on AI and Fermentation Modeling
TSUNAN SAKE BREWERY President Kengo Suzuki gave a lecture on September 29, 2026, at the 15th Lecture Meeting of the Kansai Joyukai, an association of sake brewing engineers based mainly in the Kansai region. The meeting was held at Kyoto Terrsa in Kyoto under the theme “Shin Nihonshu,” or new sake, with talks on tradition and innovation in sake brewing.
Suzuki reviewed how the brewery has used Smart Brewing, its generative AI system, to make a junmai daiginjo from Uonuma Koshihikari table rice. He also introduced Super Smart Brewing, which the brewery is now developing to simulate how rice, water and temperature conditions shape the finished sake.
Lecture overview
– Meeting: 15th Lecture Meeting of the Kansai Joyukai (fiscal 2026)
– Theme: Shin Nihonshu: The Next Era of Sake Brewing, Shaped by Tradition and Innovation
– Date: Tuesday, September 29, 2026
– Venue: Kyoto Terrsa, Minami-ku, Kyoto
– Title: Taking On Shin Nihonshu: How Smart Brewing and Science Are Shaping the Next Era of Sake Brewing
– Speaker: Kengo Suzuki, President and Representative Director, TSUNAN SAKE BREWERY
Other lectures at the meeting covered the history and challenges of Yamada Nishiki sake rice, brewing with a wider range of raw materials, and sake culture in the Edo period.
Coming to sake from microalgae research
Suzuki began his career as a microalgae researcher. He co-founded Euglena Co., Ltd. in 2005 and worked on the outdoor mass cultivation of Euglena for food. He became a shareholder of TSUNAN SAKE BREWERY in 2019 and its President and Representative Director in December 2023.
In sake brewing, saccharification and fermentation take place together in one tank, a process known as multiple parallel fermentation. The toji (master brewer) and brewery staff follow it through Baumé readings, mash temperature and touch, and adjust their work each day. Much of that judgment rests on individual experience, while the properties of rice change from year to year with the climate and the number of brewers is falling. Suzuki said brewers increasingly need ways to keep the process under control as these conditions change.
The challenge: a junmai daiginjo from table rice
As a small brewery, TSUNAN SAKE BREWERY cannot run dozens of trial brews in parallel, which led it to rely on data and models. Its flagship GO GRANDCLASS Uonuma Koshihikari Edition is made from 100% Koshihikari polished to 50% of its original weight. Table rice poses three problems for brewing:
– Stickiness: the grains clump during koji-making, which tends to produce koji with weak enzymes.
– Composition: the rice contains more protein and fat, which can break down into off-flavors and bitterness.
– Solubility: the rice dissolves poorly in the mash, which can slow saccharification and stall fermentation.
Smart Brewing
The brewery built Smart Brewing in 2023 to support decisions with generative AI. Suzuki said the key is less the AI itself than the knowledge it draws on. To reduce errors, the brewery combined the AI with retrieval-augmented generation (RAG) and organized the sources it consults.
Since then, the brewery has added its own data, including spectral reflectance measurements and mass spectrometry data on koji. On site, staff use a tool built by the brewery to time the washing and soaking of rice, a step that needs particular care with table rice. The brewery also uses AI to examine why each finished sake turned out as it did.
Super Smart Brewing
Super Smart Brewing is a fermentation simulation and database intended to help brew sake outside Japan, and eventually beyond Earth.
It is built on a mathematical model that describes multiple parallel fermentation with ordinary differential equations, based on a formulation by Yataro Nunokawa (1977). The model tracks how steamed rice dissolves, how sugars and alcohol form, and how aroma esters form and evaporate. It is combined with data assimilation using an ensemble Kalman filter, which uses sparse measurements to update the model’s internal states and reaction rates step by step.
Comment
Kengo Suzuki, President and Representative Director, TSUNAN SAKE BREWERY
“Thank you for the opportunity to speak to engineers who have supported sake brewing in Kansai. In our trials so far, a process proposed by AI on its own has never turned out to be the best one. Even so, I hope that a model refined with feedback from experience can record reproducible data and carry it to the next place and the next generation. I want Japan’s fermentation technology, with sake at its center, to contribute to well-being around the world. As people expand where they live, including into space, I will keep working so that the transformation of materials by microorganisms is carried forward not only as technology but as culture.”
Next steps
TSUNAN SAKE BREWERY will continue adding its own data to Smart Brewing. For Super Smart Brewing, it is improving the model to handle residual sugar and recipe elements so that it can also reproduce sweeter sake. It will also continue research on nanoparticles in sake and on materials made from sake lees.
About TSUNAN SAKE BREWERY
TSUNAN SAKE BREWERY is a sake brewery in Tsunan, Nakauonuma District, Niigata Prefecture, one of the snowiest areas in Japan. It brews with natural water from the surrounding mountains, which rise to about 2,000 meters. Under its brand concept “Brew for Future,” it makes traditional sake from locally grown Gohyakumangoku sake rice and Premium Table Rice Sake from locally grown Uonuma Koshihikari.
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