Our water is a naturally sweet and gentle spring water, filtered by volcanic ash layers (the Shirasu Plateau) formed by the eruptions of active volcanoes such as Sakurajima. Over the course of many years, it slowly naturally filters through these volcanic ash layers and is heated by magma deep underground. Emerging from a depth of 750 meters at a temperature of 47 degrees Celsius, it is enriched with electrolytes and minerals.
*Photo Credit: Mitsuo Komoriya unsplash
Where does ONSENSUI 99
come from?
1. Natural Filtration
A key feature of ONSENSUI 99 is its natural filtration through volcanic ash layers. This process imparts a distinctive sweetness and gentleness to the water, ensuring high purity.
the Shirasu Plateau
One essential factor that cannot be omitted when explaining ONSENSUI 99 is the Shirasu Plateau formed by volcanic activities. In Kagoshima area, the deposits, resulting from the massive pyroclastic flows and fallout during the Aira Caldera eruption, occurred approximately 29,000 years ago, extensively blanket the entire Kagoshima Prefecture. Volcanic ash has been falling since that period, leading to the formation of the Shirasu Plateau.
Sakurajima
There are 11 active volcanoes in Kagoshima Prefecture, but Sakurajima, which floats in Kagoshima Bay, is a symbol of Kagoshima and is globally renowned as an active volcano that continues to be active to this day.
by Hiromi Matumoto,
The impact of volcanic eruptions on material degradation., Boshoku Gijutsu, 33, 419-420 (1984)
Mineral rich in Sakurajima volcanic ash
The chemical composition of Sakurajima volcanic ash consists of approximately 55.5% SiO2, around 17% Al2O3, about 5.5% FeO, and approximately 1.5% Fe2O3. It also contains approximately 3% MgO, about 6% CaO, around 3% Na2O, and approximately 1.3% K2O. Additionally, it contains various heavy metal elements such as As, Co, Pb, Sn, Zn, V, Cr, Cu, Hg, making it rich in minerals.
© K. P. V. B
Sedimentary Rocks and hornfels
The city of Tarumizu is characterized by its mountainous terrain, which is formed from sedimentary rocks of the Shimanto Group dating back approximately 150 million to 65 million years ago. In the Sarugajyo Valley of Moutain Takakuma in Tarumizu, white granite is exposed. These rocks were formed when magma intruded into the deep layers of sedimentary rocks and slowly cooled, eventually rising to the surface. The surrounding sedimentary rocks have become hard hornfels due to the heat from the magma.
the Water Cycle
Water undergoes a short-term cycle, evaporating from the sea to form clouds, raining down onto mountains, rivers, and groundwater, and eventually returning to the sea.
Natural filtration by mineral-rich volcanic layers
Groundwater, especially when extracted from deep underground, passes through numerous geological layers over centuries, gradually transforming into high-purity water.
2. Volcanic Hot Springs
ONSENSUI 99 is sourced from hot springs influenced by active volcanoes. Emerging from a depth of 750 meters at a temperature of 47 degrees Celsius, the water gains a unique flavor and is enriched with electrolytes and minerals, contributing to its health benefits.
Kirishima Hot Spring © K. P. V. B
Hot Springs
Hot springs can be found all over the world, but Japan is renowned as one of the leading “hot spring nations” globally. It boasts over 21,000 hot spring sources with an astonishing flow rate of approximately 2.6 million liters per minute in 2018.* Moreover, hot springs with temperatures exceeding 42 degrees Celsius account for 47% of the total. Japan boasts 3,085 accommodation facilities with hot springs, and many of these are conveniently located along volcanic belts, ensuring a consistent source of thermal heat.
The quality of hot springs
Japan experiences distinct seasons, and phenomena like the rainy season, typhoons, and snowfall bring abundant water resources to the Japanese archipelago. This diversity allows for enjoying different water qualities depending on the location. The quality of hot springs varies depending on their source, and the quality of hot spring water is referred to as “spring water quality.”
Magma and underground water
Magma continues to emit heat and volcanic gases until it cools completely. When underground water comes into contact with this heat and gas, it becomes heated, pressurized, and rises toward the surface through fissures in the ground. This is how hot springs are formed. Hot spring water contains water from the magma (virgin water), along with other constituents, and it also dissolves minerals from the surrounding rocks.
Tamatebako ONSEN © K. P. V. B
25 degrees celsius or higher by the Earth’s internal heat
ONSENSUI (Hot spring water) refers to underground water that is heated to 25 degrees Celsius or higher by the Earth’s internal heat.* What distinguishes it from tap water is its rich mineral content, including calcium, magnesium, sodium, and potassium.
*the Japanese Hot Spring Act
3. Nature gives our water everything it needs
Through the combined effects of natural filtration and volcanic activity, ONSENSUI 99 receives everything it needs directly from nature. This comprehensive natural process results in water rich in essential electrolytes and minerals, making it a highly nutritious beverage.
Our water is filtered over an extended period through the Shirasu Plateau, the layers of tuff deposited by the mineral-rich volcanic ash of Sakurajima and historical volcano activities.
Our water, the primitive water, enriched with electrolytes and minerals is natural hot spring water, drawn from 750 meters underground in Tarumizu City, near Sakurajima, Kagoshima Prefecture, at a temperature of 47 degrees Celsius.
Natural Water
Bottled Water
