ゆのつぼ温泉
Yunotsubo OnsenOperated by · 由布市
湯
Simple
- Color
- colorless and clear
- Taste
- tasteless
- Odor
- odorless
Sodium Bicarbonate-Chloride spring
pH 8.0Weakly alkalineHot source · 57°CHigh silica
Composition fingerprint0.7 g/kg dissolved · Hypotonic
Na⁺81
HCO₃⁻47
Cl⁻34
SO₄²⁻19
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Bicarbonate HCO₃⁻
- "soda" — softens skin, leaves it smooth.
Known good for
- Aches & jointsstiff shoulders
- Smooth skindry, rough skin
- Recoveryfatigue, stress
Yunotsubo Onsen rises in the Kawakami district of Yufuin as a simple thermal spring: weakly alkaline, soft on the skin, and lightly mineralized at 685 mg/kg of dissolved solids, so it stays gentle enough for a long, unhurried soak. What lifts it above plain water is silica — metasilicic acid at 214 mg/kg, generous enough to leave the thin moisturizing film that places this source squarely in Japan's beauty-water family. The certificate's sample was drawn at the storage-tank outlet rather than at the wellhead, so the figures describe the water close to the state in which it reaches the bath.
Sampled at delivery pipe·Analyzed Mar 26, 2020·公益社団法人大分県薬剤師会検査センター·Cert no. 大薬検 第 7R-20030007号