Kawachinagano City, located in the southeast of Osaka Prefecture in the Minami Kawachi region, is a city rich in nature, with approximately 7% of the city being covered by forests. It has flourished as a key transportation hub since ancient times, and various cultural and historical legacies remain. With the Ishikawa and Iwamigawa rivers flowing through the city, it is also rich in water sources. Due to its geographical features, Takihata Dam was completed in 1981.

The only sake brewery in Kawachinagano is Saijo Limited Partnership Company, founded in 3. During the Edo period, it was known as "Miki Masamune," and throughout the Taisho and Showa periods, it was known as "Nami no Tsuru." In 1718, with the cooperation of Amano-san Kongo-ji Temple, it revived the traditional "Amanosake" brand. Today, it is known only to those in the know.

The "Dam Aged Sake" project, which began in 2016, is a collaboration between two of Kawachinagano's proud "assets."

From the surface of the quiet lake bottom

The morning of May 2025, 5. A dozen people gathered in front of the Takihata Dam Management Office: Kawachinagano city officials, the prefecture's dam manager, President Saijo Yozo, members of the press, and the author and a member of the Sake World team. The lifting operation was open only to members of the press. For safety reasons, everyone wore helmets and life jackets.

After putting them on, we stepped into an area normally off-limits to the general public, heading up a steep slope behind the office to the boat dock. There was a simple incline made of steel rails and wires, allowing the boat and cart to slide down onto the lake together.

After the dam staff lowered the boat, they divided the group into several groups and selected the "crew members." They took turns descending the steep stairs to the lake surface. It felt almost like a "cliff." They descended carefully, being careful of where they stepped.
The creaking of metal accentuated our pounding heartbeats for several minutes as we slid along the swaying pontoon and into a small boat.

The group travels by small boat to a "floating island" set up for dam maintenance.
Although it was late May on the day of the interview, the weather felt like early summer. When I put on the life jacket and helmet, I started to sweat.

From the floating island, you can see the main part of the dam, which you would not normally be able to see. This alone is a valuable experience.

After the group "landed" on the floating island, the work of salvaging finally began. Directly below, at the bottom of the lake where the water temperature is 8-10 degrees Celsius, 80 XNUMX bottles that will become "Dam Aged Sake" have spent half a year. President Saijo takes the lead as he pulls in the ropes that are connected to the cases.

A green plastic sake case emerged from the greenish water. President Saijo spoke with a big smile.
"Water has a higher thermal conductivity than air, so it cools evenly from all sides. The flavors come together in layers."

With Kawachinagano City's symbolic character "Mockle"

The cycle is that the sake is put into the ground in December every year and then taken out the following May.

The first time, they didn't know how to pack the alcohol so that it would sink to the bottom of the lake, so they had to fumble around, which resulted in a lot of air pockets forming between the packing materials, which caused the alcohol to not sink.

"Nobody does that."

After the salvage operation was completed, I spoke with President Saijo and a Kawachinagano city official.

It all began in 2012, when Nakatani, head of the Takihata Dam branch office, came up with the idea of "sake aging."

Nakatani first proposed to a winery in Kashiwara, but was turned down, saying, "It doesn't make sense to make wine from Kashiwara at a dam in Kawachinagano." So he turned to the local sake brewery, Saijo Limited Partnership Company.
Incidentally, President Saijo had been considering aging his company's own brand of sake, "Sobousake," in the rim tunnel* of Takihata Dam for some time.

*A tunnel constructed to ensure safety from obstacles that threaten the stability of a dam, such as cracks in the rock mass or water leaks from faults.

Then, the then branch chief, Nakatani, gave an unexpected response.

President Saijo"Nakatani-san suggested, 'If you're going to do it, why not submerge it in water? No one has done that yet.' I had never thought of that. I was surprised."

Thus, the lake bottom maturation plan began to move forward.
However, because Takihata Dam is a drinking water and irrigation dam, obtaining permission was difficult. However, Nakatani, the branch chief, compiled all the necessary documents, including those in accordance with the River Law, and managed to complete the two-year test maturation period.

His tireless work is truly that of a super civil servant. Furthermore, in keeping with the principle that "if we use public infrastructure, we should give back to the local community," it was decided that the dam-aged sake would be offered as a gift in return for hometown tax donations in Kawachinagano City.

The first event was held in 2016. "NHK and Kyodo News came and reported it extensively, calling it 'the first lake-aged sake in the country.'" President Saijo said, expressing his excitement. Apparently they also filmed the event from above by helicopter.

The 120 limited edition gifts "sold out in an instant," according to President Saijo. Since the following year, it has grown into a popular project that is mainly attended by repeat customers.

"I'll be watching closely this year too."

After completing the lifting work, President Saijo's face softened.

President Saijo"It's interesting, but every year some kind of incident always happens. I think it's like a signal from the late Mr. Nakatani saying, 'I'll be watching closely from here this year too.'"

Hearing this, everyone involved burst into laughter. It seemed as though the spirit of Director Nakatani is still alive in everyone's hearts.

Saijo Limited Partnership Company first marketed Amano Sake as "dam-aged sake" in 2016, but at the time it was actually the first such attempt in Japan.

Being a pioneer is bound to face difficulties, but the reason they have not given up on this project despite the numerous obstacles they have come up against lies in the feelings each member had at the time, which have taken root deeper than the bottom of the lake in their hearts.
It's heartwarming to think that each and every one of these plants, nurtured in the silence and deep green water, contains its own thoughts and stories.

I myself immediately purchased some "Amano Sake Takihata Dam Lake Bottom Aged Sake" that had been aged for half a year at the bottom of the Takihata Dam lake as a hometown tax donation and tried tasting it.

The specifications are pure rice ginjo unfiltered unpasteurized sake with a rice polishing ratio of 60%. It has a pale lemon green appearance.

The aroma is a mix of cool prince melon and green apple, layered with the soft, sweet scent of rice reminiscent of rice flour and marshmallow, and gradually the subtle spice of cinnamon and cloves emerge, adding depth.

The taste is silky smooth, with the gentle sweetness of steamed rice and habutae mochi at its core, and the juicy flavors of white peach and ripe figs. In the middle, the richness of lactic acid like mozzarella and Greek yogurt is added, giving you a sense of the roundness that comes from aging at the bottom of a lake.

The aftertaste has woody nuances of cypress, cedar, and umami, the aroma of fresh hazelnuts, and a subtle but umami-supporting flavor of shimeji mushroom stock, all of which quietly lingers, complete with a subtle touch of honey.

The balance of sweetness, sourness, and umami is amazing! I was simply moved, thinking that this must be the power of lake bottom aging.

Current location in 8 years

While witnessing the salvage work and listening to what was being said, it was clear that President Saijo, the Kawachinagano city official, and the Takihata Dam staff all worked together in perfect harmony.

"Amanoshu Takihata Dam Lake Bottom Aged Sake" is a story-based sake born from an unusual collaboration between public infrastructure and a sake brewery. The layered flavors that come from six months of underwater aging are creating a new cycle for the local economy and tourism.

Incidentally, the rim tunnel aging originally conceived by President Saijo is also being implemented in the "Sobousake" produced by Saijo Limited Partnership Company. This is a reproduction of the sake beloved by Toyotomi Hideyoshi during the Azuchi-Momoyama period.

The average temperature inside Takihata Dam's rim tunnel is about 12°C, and the wine is aged in a natural cellar.

Rim Tunnel Entrance

The eighth release of the dam-aged sake was, as in previous years, distributed exclusively through the hometown tax donation program in Kawachinagano City, and donors were also given a "limited edition dam card."

This year, a special gift will be prepared in return, which will include a meal voucher worth 10,000 yen to the sake brewery restaurant "Tenkuu" run directly by Saijo Limited Partnership Company. Sales are going well.

Tenku, a sake brewery restaurant operated by Saijo Limited Partnership Company (Photo provided by Kawachinagano City)

Takihata Dam aged sake has become a symbol of the Kawachinagano brand.

The eight-year journey as a pioneer has shown the possibilities of both creating new markets and branding the region. When I pulled one out from the bottom of the lake, I could feel the story of water, time, and human wisdom unraveling on my tongue.

I look forward to seeing this project mature further.

Kawachinagano City Hometown Tax Website
https://www.city.kawachinagano.lg.jp/soshiki/74/82491.html

Saijo Limited Partnership Company Website
https://www.amanosake.com

Takihata Dam website　https://www.pref.osaka.lg.jp/o120170/minamikawachinm/m_index/k_takihatadam.html

Original Japanese Writer/English Translator: Ayuko Yamaguchi
Sake journalist, WSET Sake Educator, international sake sommelier, and lecturer in Japanese sake studies. Based in Osaka, she teaches the WSET Sake course in English and writes in both Japanese and English. She also holds WSET Spirits Level 2019 (2023) and covers spirits alongside sake.