Why Is ONSENSUI99 So Mellow and Easy to Drink? Explaining the Characteristics and Reasons Behind Ultra-Soft Water
Why ONSENSUI99 Hot Spring Water Tastes Smooth and Easy to Drink
Many people describe ONSENSUI99 hot spring water as "very easy to drink and smooth."
The reason for this is not just a sensation, but lies in the very structure of the water quality.
Reason 1: World-Class Ultra Soft Water (Hardness 1.7)
The biggest characteristic of ONSENSUI99 hot spring water is its extremely low hardness value of 1.7.
Water hardness indicates the amount of calcium and magnesium.
- Soft water: Gentle and light mouthfeel
- Hard water: Strong mineral taste
ONSENSUI99 hot spring water has an exceptionally low hardness, making it
👉 a very soft and easy-to-drink water with no peculiar taste.
Reason 2: Naturally Alkaline (pH 9.5-9.9)
This water is natural alkaline water sourced from deep underground in Tarumizu City, Kagoshima Prefecture.
Its pH balance is naturally formed as it passes through geological layers over a long period of time.
As a result:
👉 It has a mellow, smooth taste.
Reason 3: Natural Filtration by Shirasu Plateau
Kagoshima's Shirasu Plateau is a special geological formation derived from volcanic ash.
Characteristics:
- Porous and naturally filtered
- Forms water with few impurities
- Groundwater is generated over a long period of time
👉 This leads to clear water quality with no off-flavors.
Reason 4: Gentle Mineral Balance
ONSENSUI99 hot spring water has a natural, not excessive, mineral balance.
Therefore:
- Light mouthfeel
- Clean aftertaste
- Doesn't tire you out from drinking
👉 Making it water that is easy to drink daily.
Why even people who dislike water find it easy to drink
Common reasons why people dislike water are:
- Strong mineral taste
- Heaviness or peculiar taste
- Lingering aftertaste
ONSENSUI99 hot spring water has fewer of these characteristics, so:
👉 It is perceived as "water that even those who dislike water find easy to drink."
Ease of drinking in everyday situations
Situations where the difference is particularly noticeable:
- First glass in the morning
- Hydrating at room temperature
- During meals
- Water for brewing tea and coffee
👉 The difference is especially noticeable at room temperature.
Difference from overseas (Soft water culture)
Japanese water is often soft water, while some regions overseas have hard water.
Therefore:
- Japanese water → Light and gentle
- Overseas water → Strong mineral taste
This creates a difference in experience.
ONSENSUI99 Hot Spring Water Quality Data
- pH: 9.5-9.9 (Naturally alkaline)
- Hardness: 1.7 (Ultra soft water)
- Source: Tarumizu City, Kagoshima Prefecture
- Geological formation: Shirasu Plateau
Summary
The reasons why ONSENSUI99 hot spring water is smooth and easy to drink are the following three:
- Ultra soft water (Hardness 1.7)
- Natural alkalinity (pH 9.5-9.9)
- Natural filtration by the Shirasu Plateau
These combined create
👉 a gentle water with no peculiar taste.
ONSENSUI99 hot spring water is a form of water created by its natural environment.
