渋大湯
Shibu O-yuOperated by · 渋温泉旅館組合
Mixed source
- Color
- slightly turbid pale yellow
- Taste
- metallic iron taste with a slight saltiness
- Odor
- not recorded
Sodium-Calcium Sulfate-Chloride spring
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Sulfate SO₄²⁻
- "gypsum / Glauber's salt" — vessels and wound healing.
- Aches & jointsstiff shoulders
- Circulationtired legs
- Warmingcold sensitivity
Shibu O-yu is a blended source — the certificate names it as a mix of the O-yu source and the Shibu Onsen combined source — and the sample was drawn at the bath spout rather than at the wellhead. Chemically it is a sodium-calcium sulfate-chloride water: sulfate gives it quiet body, chloride adds a salty, heat-retaining edge, and 1,257 mg/kg of dissolved solids puts it in the moderately mineralized band with noticeable substance. It is weakly acidic, faintly turbid pale yellow at the spout, with a metallic iron taste and a light saltiness on the lips. Metasilicic acid at 148 mg/kg leaves the kind of thin silica film that makes skin feel smoother afterwards.
Sampled at bath inlet·Analyzed Jun 18, 2025·一般社団法人 上田薬剤師会 検査センター·Cert no. 中7-7（No. 814）