Factory Guide


Providing information on health and beauty, UONUMA KOJI SALON is a place to let the visitors be calm and relaxed. There can be found a cafe which serves koji amazake directly delivered from the factory and our original koji amazake soft ice-cream, and a library specialized on fermented foods, a curated shop with items to enrich everyday life, and a kids’ corner, where young people can have fun learning about koji amazake. The SALON has something for every age group to enjoy.
(No booking required)



Enjoy koji amazake, our original koji amazake soft serve ice-cream, seasonal smoothies and more at the Cafe.


We’ve gathered books on amazake, koji and fermentation. Books on the culture and history of Uonuma can also be perused.


Here you’ll find a wide variety of products for sale, including koji amazake and food-related items.


Koji amazake soap making workshops are offered. Take the soap you make home with you as a souvenir.
・Advance bookings required for the koji amazake soap making workshops. Charge: 1,000 yen (incl. tax) per person.
・Bookings accepted for groups of up to 8 people.
・Workshops must be booked together with a rice koji factory tour. Workshops cannot be booked alone.


Fine products made with Japanese materials and skilled craftsmanship are available at the UONUMA KOJI SALON Shop.

"Kittachi Yunomi" Tea cups

We created cups for green tea that can be used just as easily as a mug. Made from the fine clay of the Iga region of Mie Prefecture, each cup is wheel-thrown by an artisan.

"Inban Hashi-Oki" Chopstick rests

The glossy white porcelain base is Hasami ware made using Japanese pottery stone. A translucent overglaze on top of the transferred designs enhances their beauty.

"Inban mamezara" Small plates

Beautiful small dishes made by the Shiratakegama pottery in Hasamicho, Nagasaki Prefecture. Designed with today’s lifestyles in mind, these dishes have delicate patterns that will brighten your dining table every day.

"Miyajima" Woodwork

Cut from Japanese timber and crafted individually by artisans, each piece has an untreated surface, making it smooth to both the eye and the touch.


In this theater room, a film about Uonuma Jozo can be seen. The theater is equipped with 48 seats and the 7.1 surround sound system, enabling a true experience of Uonuma Jozo.
(No booking required)

Rice Koji Factory

The process of creating rice koji can be observed at our rice koji factory. See how Uonuma Jozo’s rice koji is made, including one of the world’s largest rice steamers and the disc-type koji making equipment that enables the world’s largest output.
(Booking required)

The Production Process

How Koji Products are Made

  • 1

    Storage and sorting

    After polished rice is brought to a stainless tank in large flexible container bags, foreign substances are removed by a sorting machine.


    Steeping tank and rice steamer

    Rice is soaked in tanks and in 10 hours, it is steamed from below by a horizontal rice steamer. The steamed rice is cooled on conveyors and then seeded by sprinkling equally Aspergillus oryzae.


    Circular Koji Production Facility

    In this huge circular facility, the seeded steamed rice is mixed slowly and carefully by feathered blending devices. This circular koji production facility is among the largest in the industry.

  • 4

    Stock room

    Only koji in equal and good quality is stocked in the room after removing any lumps by oscillating sieve and foreign substances or defective product by color sorter. The room temperature is kept with 15℃ to control activation of Aspergillus oryzae.


    From Rice Koji to Koji Amazake

    Koji Amazake is prepared by mixing koji in good quality and water of Uonuma and finalized with strict temperature control. Finished Koji Amazake is heated to prevent breeding of unwanted bacteria, then cooled and filled in containers.
    ・Not open to tour visitors


    Shio Koji and Shoyu Koji preparation

    Preparation of fermented seasoning product like Shio-koji and Shoyu-koji mixing Koji with salt, water or soy sauce.
    ・Not open to tour visitors

  • 1

    Storage and sorting

    Polished rice is fed into a stainless steel tank by large flexible container bag then passed through three sorters to remove foreign objects.


    Steeping tank and rice steamer

    The rice is steeped in the tank for 10 hours, then steamed from below using a horizontal rice steamer. The steamed rice is cooled on a conveyer, then inoculated by spraying it evenly with koji (Aspergillus oryzae) spores.

  • 3

    Disc-type koji making equipment

    The inoculated steamed rice is mixed slowly in a massive disc using a winged blade. Producing dried rice koji, this disc-type koji making equipment is one of the largest in the industry.


    Stock room

    Koji that has clumped is removed using a vibratory sieve, then foreign objects and poor koji is removed using a color sorter. The remaining uniform, high quality koji is then stocked. The stock room is kept at a consistent 15°C to arrest koji fungus activity.

  • 5

    From rice koji to koji amazake

    Koji amazake is made by fermenting the resulting high-quality koji with Uonuma’s soft water under strict temperature control until it becomes koji amazake. The finished koji amazake is heated to prevent bacterial growth, then cooled.
    ・Not open to tour visitors


    Shio koji and shoyu koji fermentation

    Fermented condiments such as shio (salt) koji and shoyu (soy sauce) koji are fermented by adding salt and water or soy sauce to rice koji and maturing it.
    ・Not open to tour visitors