【Kuroyo Shinshu Caviar Guide】A clear umami in every grain. The "supreme caviar" born from Kuroyo Water and unheated processing.

From Nagano to the World: Supreme Caviar Refined by the Famous 'Kuroyo Water'

The distinguishing feature of Kuroyo Shinshu Caviar lies in its pure, clear taste without any off-flavors, and its high purity that brings out the inherent umami of the roe.

Supporting this quality is the famous 'Kuroyo Water' that springs forth in Nagawa-machi, Chiisagata-gun, Nagano Prefecture.

This region has been known as a production area for high-quality obsidian since ancient times, and the water that has been refined over many years through these geological layers is named 'Kuroyo Water'.

This ultra-soft water, with a hardness of 17 and almost no organic matter, does not interfere with the taste of ingredients and has the property of enhancing their umami. This characteristic is leveraged in the caviar, resulting in a clear, pure taste without any impurities.

Many people from both within and outside the prefecture visit to draw 'Kuroyo Water', which is ultra-soft water with a hardness of 17 and almost no organic matter, so to speak, 'natural ultra-pure water'.

This pure water is known for not interfering with the taste of ingredients in cooking, such as rice, coffee, and dashi, and for bringing out their inherent umami. Furthermore, water with similar characteristics is extremely rare both domestically and internationally, making it a precious natural resource.

We raise sturgeons in an environment where 3 tons of Kuroyo Water gush out every minute. The abundant water volume and high purity provide a 'detox effect' that suppresses the unique fishy odor of sturgeon, successfully bringing out the natural umami and flavor of the ingredients.

Sturgeons, an ancient fish, and obsidian, cherished by people since the Paleolithic age. The caviar born from the 'Kuroyo Water' created by these two brings an unprecedented clear taste with a deep black luster.

Experience a superior caviar. Thoroughly purified 'Kuroyo Water' creates an environment free of impurities in the caviar, while unheated processing seals in the natural texture and umami of the roe.

Crystal-clear taste born from hybrid land-based aquaculture.

Kuroyo Shinshu Caviar is born from 'hybrid land-based aquaculture' that fuses digital technology with the blessings of nature.

During the juvenile stage, the fish are managed in a fully closed system using the international patented technology 'POSC-RAS®' by Aesing Co., Ltd. in Shinshu. Water quality and temperature are thoroughly controlled to ensure stable growth during the delicate period.

In the final stage, natural water, welling up through obsidian layers, is continuously flowed through. This removes the subtle fishy odor unique to sturgeon, bringing out the natural umami of the ingredients.

Protecting 'life' with the latest system and refining 'taste' with traditional spring water. These two environments support the quality of the Kuroyo brand.

QUALITY: Two-stage quality design that prevents impurities.

The reason why 'Kuroyo Shinshu Caviar' is praised by professional chefs as 'surprisingly clear' is its two-stage quality design, which switches the aquatic environment according to the growth stage.

①【Rearing】Thorough management with POSC-RAS® (Protection)

During the delicate and vulnerable juvenile stage, management is conducted using Aesing Co., Ltd.'s international patented system 'POSC-RAS®' in Okaya City. Ozone control suppresses viruses and bacteria, promoting stable growth in a high-temperature environment. This maximizes the inherent vitality of the sturgeon.

②【Finishing】Refining with Kuroyo spring water (Purification)

In the final stage before egg collection, the sturgeons are moved to a pond with ultra-soft natural water filtered over many years through the obsidian layers of Wada Pass. By exposing them to 3 tons of continuously flowing natural water per minute, subtle odors remaining in the flesh and roe are removed.

③【Result】Clear, pure taste without impurities.

This 'Digital (management) × Nature (natural water)' process achieves the creamy sweetness inherent in the roe and a transparent aftertaste. The result is a clear caviar without any off-flavors.

STORY: Following in his father's footsteps, going beyond with technology.

Overcoming the crisis of business closure due to the COVID-19 pandemic, a challenge for revival was taken. Representative Kyosuke Higashikubo's goal was to "maximize the value of Kuroyo Water, which my father loved."

"I want to protect lives that couldn't be protected by traditional flow-through systems alone, using the latest technology. And finally, finish with the best water – I believe that is a tribute to my father."

The current aquaculture style, which combines the fully closed aquaculture system 'POSC-RAS®' with finishing using Kuroyo Water, was born from this vision.

Rich richness revealed after eliminating impurities. A grain where Shinshu's nature and technology culminate.

INNOVATION: Fully managed aquaculture to protect fry, realized by technological innovation.

The most critical period that affects the quality of sturgeon is the delicate and vulnerable fry stage.

Kuroyo Shinshu Caviar introduces the fully closed land-based aquaculture system 'POSC-RAS®' at this stage, achieving thorough management unaffected by external environments.

①【Safety】Thorough management to reduce the risk of fish mortality.

By keeping water quality and temperature constantly optimal, the risk of fish mortality, which is highest during the fry stage, is significantly reduced. Compared to conventional methods, fish mortality is reduced.