湯元屋旅館
Yumotoya Hotel SpringOperated by · 湯元屋旅館
酸
Acidic
+ Sulfate
- Color
- faintly milky white, lightly cloudy
- Taste
- strongly sour with a strong metallic note
- Odor
- almost odorless
Calcium-Hydrogen Sulfate spring
pH 2.4AcidicHot source · 91°CUltra-acidicHigh silica
Composition fingerprint1.4 g/kg dissolved · Hypotonic
Ca²⁺34
H⁺26
Al³⁺14
SO₄²⁻93
◀ CationsAnions ▶
- Calcium Ca²⁺
- settling and calming; can leave a white mineral bloom.
- Sulfate SO₄²⁻
- "gypsum / Glauber's salt" — vessels and wound healing.
Known good for
- Skin conditionsatopic skin, eczema
- Circulationtired legs
- Aches & jointsstiff shoulders
- Sensitive-skin cautionbroken or dry skin
An ultra-acidic calcium sulfate spring (pH 2.4) rising at 90.7 °C, among Japan's hottest natural sources. The water carries a faintly milky white, lightly cloudy appearance at the wellhead with a strong sour and metallic tang, sharp enough to sting on contact. Metasilicic acid at 396 mg/kg adds a noticeable silica film, typical of the Myoban onsen field famous for its skin-conditioning waters.
Sampled at wellhead·Analyzed Jul 4, 2019·公益社団法人 大分県薬剤師会·Cert no. 大薬検 第7R-19060015号