天満温泉組合
Tenman Onsen CooperativeOperated by · 天満温泉組合
- Color
- colorless and clear
- Taste
- very faintly salty
- Odor
- almost odorless
Sodium Bicarbonate-Chloride spring
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Bicarbonate HCO₃⁻
- "soda" — softens skin, leaves it smooth.
- Smooth skindry, rough skin
- Aches & jointsstiff shoulders
- Warmingcold sensitivity
A sodium-dominated bicarbonate-chloride spring — jūsō-sen in the older nomenclature, which the certificate still records as a salt-bearing soda water. Alkaline and soft on the skin, it sits squarely in Japan's beauty-water family, with the smooth, slippery touch bicarbonate springs are known for. The water is colorless and clear with only the faintest salty note on the tongue, while the chloride fraction adds the heat-retaining finish that keeps warmth in after the bath. The source itself ranks among Japan's hottest, and a generous 166 mg/kg of metasilicic acid leaves the kind of silica film that makes skin feel noticeably smoother.
Sampled at delivery pipe·Analyzed Oct 5, 2023·公益社団法人大分県薬剤師会·Cert no. 大薬検 第7R-23090006号