In 2024, Traditional knowledge and skills of sake-making with koji mold in Japan was inscribed on UNESCO’s Intangible Cultural Heritage list, bringing global attention to honkaku shochu, sake, and awamori. In this series, “Dr. Shochu” Masahiko Shimoda—who has spent many years at Sanwa Shurui, maker of the honkaku barley shochu iichiko, both as a technician and as an executive—offers a multifaceted look at the appeal of honkaku shochu. In this first installment, we begin by exploring why Dr. Shimoda calls honkaku shochu the “Miracle Spirit.”
As told by: Masahiko Shimoda, Chairman of Sanwa Shurui Co., Ltd. /
Composition: Kenji Inoue, Contentsbrain
● About Honkaku Shochu
Shochu, Japan’s traditional distilled spirit, comes in two types: single-distilled shochu, made using a single still, and continuous-distilled shochu, made using a continuous still. This series focuses on honkaku shochu, a category within single-distilled shochu.
As the name suggests, single distillation is a production method in which the mash is distilled only once. Honkaku shochu is defined as a spirit made by fermenting designated ingredients with koji and water, then distilling the mash once in a single distillation still. It must have an alcohol content of 45% or less and contain nothing other than water—no additives of any kind. Common ingredients include rice, barley, sweet potatoes, and buckwheat, each imparting its own distinctive aroma and flavor.
Continuous-distilled shochu, also known as korui shochu, is made by passing fermented mash through a column-type continuous still capable of repeated distillation, producing highly purified alcohol with nearly all impurities removed. Water is then added to reduce the alcohol content to below 36%, as stipulated under Japan’s Liquor Tax Law. It carries the pure taste of alcohol itself and is often used for beverages such as chuhai—a mix of shochu with fruit juice or soda water—or for making fruit liqueurs.
The “Miracle” of Honkaku Shochu – Part 1
When the Brewing Traditions of Cold and Warm Climates Met in Southern Kyushu 500 Years Ago
Hello, I’m Masahiko Shimoda from Sanwa Shurui. I was born in Oita Prefecture in Kyushu. My father enjoyed drinking, and that sparked my interest in fermentation. Leaving my hometown, I went on to enroll in the Department of Fermentation Technology (now the Department of Biotechnology in the Division of Applied Science) at Osaka University’s School of Engineering, where I studied fermentation science and microorganisms, with a focus on yeast. After graduation, I joined a sake brewery in Hyogo Prefecture. There, I learned the fundamentals of sake brewing summed up in the saying ichi-koji, ni-moto, san-tsukuri—first koji, second moto (yeast starter), third brewing—which later proved invaluable in my shochu-making career. As I will explain in detail throughout this series, honkaku shochu is also built on this same foundation of ichi-koji, ni-moto, san-tsukuri.
After working at the sake brewery for about five years, I returned to Oita and joined Sanwa Shurui. As head of the R&D Office reporting directly to the president, I devoted myself to establishing stable production technology for iichiko, a honkaku barley shochu that had only recently been launched at the time.
I believe honkaku shochu is a “Miracle Spirit”—a distilled beverage that exists today thanks to a long and winding history of constant change and evolution, which to me feels nothing short of miraculous. Let’s look back through that history and explore the miracles surrounding honkaku shochu, dividing them into three major eras (see “Honkaku Shochu Evolution Chart”).
The first of these miracles takes us back about 500 years, to the 16th century.
Barley koji, the ingredient used to make the honkaku barley shochu iichiko
The technique of sprinkling steamed rice grains with seed koji to produce koji, then brewing rice-based sake, is thought to have taken shape around the 13th century, centered in Kyoto, which was the political and cultural hub of the time. Over time, this knowledge of using koji in sake brewing spread north and south across the Japanese archipelago. Sake brewing is traditionally based on kuri—winter brewing—where low temperatures help suppress the growth of unwanted microorganisms during fermentation. However, in the southern Kyushu —Japan’s warmer southern region including Kagoshima, Miyazaki, and Kumamoto—kan-zukuri did not work well, and bacteria that degraded the quality of the sake tended to proliferate during fermentation. As a result, spoilage was common, and the climate was also unsuitable for storing the finished sake.
Around 1500, the concept of distilling alcohol reached southern Kyushu via Okinawa (then the Ryukyu Kingdom), further to the south. Today, Okinawa’s distilled spirit is known as awamori, but it had not yet been developed at that time. The forerunner of awamori was lao-rong , a distilled liquor brought from Siam (Thailand) through trade. Lao-rong was made by distilling moromi⋆1(fermented mash), and because of its high alcohol content, it could inhibit the growth of bacteria and keep well even in Thailand, where the climate is warmer than Japan’s throughout the year due to its proximity to the equator. Distilled spirits, in other words, are well suited to warm climates such as those of Thailand and Okinawa.
⋆1 Moromi (fermented mash)： refers to the mash in which koji, water, and yeast are combined in a fermentation tank and allowed to ferment.
In southern Kyushu, where stable, high-quality sake could not be produced, exchanges with Okinawa led to the adoption of distillation. The technique of distilling sake or sake mash to extract alcohol took root, meaning that the earliest honkaku shochu was kome shochu (rice shochu), made from the same rice used for sake. By contrast, in regions north of southern Kyushu, kan-zukuri was possible and good-quality sake could be brewed, so there was no need to distill it.
Thus, the cold-climate brewing traditions built on kan-zukuri and the warm-climate distilling methods that came via Thailand and Okinawa crossed paths in southern Kyushu 500 years ago, setting in motion the evolution of honkaku shochu.
Honkaku Shochu Evolution Chart (created by Masahiko Shimoda)
The “Miracle” of Honkaku Shochu – Part 2
Three Major Transformations in Shochu Production After the Meiji Restoration
The next stage in the evolution of honkaku shochu came about 120 years ago, triggered by the Meiji Restoration⋆2. This period saw three major innovations in honkaku shochu unfold almost simultaneously.
⋆2 Meiji Restoration：A political and social upheaval in Japan in the late 19th century that accelerated modernization, as Western science, culture, and ideas were actively incorporated.
The first was the introduction of new fields of study and scientific technologies from the West following the Meiji Restoration. Until then, sake brewing in Japan had relied heavily on the experience and intuition of craftsmen, but this era saw the arrival of knowledge and techniques related to microorganisms, as well as microbiology—the discipline of isolating beneficial microbes and applying them in practice. The National Research Institute of Brewing was established in 1904. Up to this point, the method of distillation, as described in the previous section, was single distillation, in which the moromi is distilled only once. In 1910, however, the column-type continuous still, equipped with multiple plates that allowed for repeated distillation inside the tower, was introduced. This made it possible to obtain purer alcohol more efficiently and laid the foundation for korui shochu.
The second was the introduction of black koji fungus from Okinawa. Until then, black koji fungus—essential to awamori production—had been discovered in the Ryukyu Kingdom and carefully guarded as a secret, never making its way to Japan. After the Ryukyu Kingdom was abolished and Okinawa Prefecture was established in 1879, formally integrated into Japan, researchers in 1901 isolated black koji fungus from the awamori production process and named it Aspergillus luchuensis.
(For more on koji fungus, see here.)
Subsequent research revealed that the citric acid produced by black koji fungus protects fermented mash from contamination by unwanted bacteria, enabling more stable alcohol production even in warm climates. As a result, from the 1910s onward, black koji fungus began to replace the previously used yellow koji fungus in honkaku shochu production in southern Kyushu.
The third innovation was the development of the niji-shikomi (secondary fermentation) method in imo shochu (sweet potato shochu) production in Kagoshima at the southern tip of Kyushu, which became established around 1910. Compared with rice or barley, sweet potatoes—the raw ingredient in imo shochu—contain more sugar, making them more susceptible to contamination by unwanted bacteria during fermentation and thus at higher risk of spoilage. Through much trial and error, producers devised the groundbreaking secondary fermentation method to address this challenge.
First, rice koji (steamed rice inoculated with koji fungus), yeast, and water are combined for the primary fermentation, allowing the yeast to multiply sufficiently. This corresponds to the second step in the sake-brewing principle of ichi-koji, ni-moto, san-tsukuri introduced at the beginning—the making of the moto (yeast starter), which follows koji . In the main fermentation, or secondary fermentation, which corresponds to the third step (tsukuri), sweet potatoes are added to the moto (primary moromi, or mash) so that yeast-driven fermentation proceeds quickly, improving both the stability and safety of the process. With the introduction of black koji fungus and the invention of the secondary fermentation method, the foundation of today’s honkaku shochu production was established.
The “Miracle” of Honkaku Shochu – Part 3
From a Humble Commoner’s Drink to One that Rivals Western Distilled Spirits
Even after modernization some 120 years ago, the status of honkaku shochu remained low.
About 50 years ago, Dr. Kinichiro Sakaguchi⋆3 —a world authority on applied microbiology known as the “God of Sake”—lamented in his book Koshu Shinshu (Old Sake, New Sake, Kodansha, 1974: first published in 1971): “When I compare the fact that Western distilled spirits are all world-famous liquors worth their weight in gold and a source of national pride, I cannot help but wonder why Japanese shochu is held in such low regard.”
⋆3 Kinichiro Sakaguchi (1897–1994)： Japanese agricultural chemist and one of the world’s leading authorities in fermentation and brewing research. Served as the first director of the University of Tokyo’s Laboratory of Applied Microbiology, professor emeritus at the same university, and deputy director of RIKEN (a national research and development agency).
Koshu Shinshu (Old Sake, New Sake) by Kinichiro Sakaguchi (photo: Koichi Mitsui)
At the time, shochu was an inexpensive way to get drunk—a “commoner’s drink.” Ironically, however, the more popular type of shochu was korui shochu. Its pure flavor, achieved by removing impurities through continuous distillation, was well regarded. Until 1949, korui shochu was called “new-style shochu,” while honkaku shochu was referred to as “old-style shochu.” In those days, honkaku shochu had an off-putting odor and cloudiness caused by oily components derived from its raw ingredients, making it unpleasant to drink.
That situation changed dramatically in the 1970s. The introduction of three post-distillation innovations—vacuum distillation, chill filtration, and polishing filtration —made it possible to produce honkaku shochu that was free of off-flavors, refined, and delicious, rivaling Western distilled spirits. Among these, the advancement that most significantly improved honkaku shochu’s quality was chill filtration technology, developed to identify and prevent oily odors. This method was popularized through the efforts of my mentor, Professor Takamichi Nishiya. Thanks to these innovations, the 1970s saw the emergence of a new and diverse range of honkaku shochu in Kyushu—far removed from the smelly, cloudy versions of the past. These included rice shochu (produced mainly in Kumamoto Prefecture), barley shochu (mainly in Oita Prefecture), and buckwheat shochu (mainly in Miyazaki Prefecture), all characterized by a bright aroma and clean flavor. It was from this period that honkaku shochu began spreading from Kyushu to the rest of Japan.
The “Miracle” of Honkaku Shochu – Infinite Expressions of Diversity
The evolution of honkaku shochu is far from over. Behind its potential for further growth lies one key factor—diversity. While there are many types of distilled spirits in the world, none can match honkaku shochu in the breadth of its variety.
First, there is diversity in ingredients. For example, the base ingredients for other distilled spirits are fixed—whisky is made from grains such as barley, and brandy from fruits such as grapes. In contrast, honkaku shochu can be made from a wide range of raw materials. According to a 2006 announcement by the Commissioner of the National Tax Agency, 53 different ingredients are officially recognized, including not only grains and tubers, but also shiso and chestnuts. Honkaku shochu can thus be made from far more than just barley, rice, or sweet potatoes, and the choice of ingredient gives each variety its own distinctive flavor.
Single distillation still
Next comes diversity in production methods. Variations in the type of koji or yeast, the choice between atmospheric or vacuum distillation, filtration techniques, and the method and duration of aging all create differences in the final product. Technological advances in production methods have continued nonstop since the 1970s. These include the development of new imo shochu varieties through sweet potato breeding, and greater diversity in barley shochu through innovations such as the all-koji fermentation method.
Another aspect of diversity you can enjoy yourself is in how honkaku shochu is served—straight, on the rocks, with water, with soda, or with hot water. In recent years, honkaku shochu has also begun to be used as a base for cocktails. The style of drinking a distilled spirit mixed with water or hot water is unique to honkaku shochu, and it also reflects its defining characteristic of being a beverage meant to be enjoyed alongside food.
Quality inspection at Sanwa Shurui
From ingredients and production methods to ways of drinking and food pairings, the possible combinations are endless. Nowhere else in the world will you find a distilled spirit that offers such a wide variety of ways to enjoy it.
Honkaku shochu is both a traditional and a modern spirit, and there is still plenty of room for further evolution. Possibilities range from long-term barrel aging, as with whisky, to producing honkaku shochu with higher alcohol content—the potential is limitless. This, too, is why I call it the “Miracle Spirit.” What honkaku shochu will be like 50 years from now is something even I cannot imagine.
Born from the fateful meeting of koji-based brewing and distillation technology, honkaku shochu holds limitless potential thanks to ongoing technical innovation and offers countless ways to enjoy it—truly a “Miracle Spirit.” In this series, I hope to share its lesser-known charms from my own perspective, creating a piece that both those new to honkaku shochu and longtime enthusiasts can enjoy.
Main references: Honkaku Shochu Seizo Gijutsu (Honkaku Shochu Production Technology, Brewing Society of Japan , 1991); Koji-gaku (Koji Science) edited by Hideya Murakami (Brewing Society of Japan, 1986); Koshu Shinshu (Old Sake, New Sake) by Kinichiro Sakaguchi (Kodansha, 1974); Sekai no Spirits: Shochu (Shochu: Spirits of the World) by Akira Sekine (Gihodo Shuppan, 2005); Shochu no Rirekisho (The Resume of Shochu) by Yoshihiro Sameshima (Ikaros Publications, 2020); Gendai Shochu-ko (Modern Shochu Studies) by Mami Inagaki (Iwanami Shoten, 1985).
PROFILE: Masahiko Shimoda
Chairman of Sanwa Shurui Co., Ltd. / Doctor of Engineering
Born in 1955 in Bungo-Ono City, Oita Prefecture. After graduating from the Department of Fermentation Technology, School of Engineering, Osaka University, he worked for a sake brewery in Hyogo Prefecture. In 1984, he returned to Oita and joined Sanwa Shurui. While engaged as a technical specialist in shochu production technology development, product development, and quality control, he earned his Doctor of Engineering degree from Osaka University in 1998. Appointed to the Board of Directors in 1999, he became the company’s first president from outside the founding family in 2017, and was appointed Chairman in 2023.
