鉄輪温泉泉管理組合
Kannawa Onsen Spring Management UnionOperated by · 鉄輪温泉泉管理組合
Sampled at mixing tank
湯
Simple
Classification
Sodium-Calcium Sulfate-Chloride spring
A weakly acidic, hypotonic simple thermal spring rising by natural flow from a bored well in the Oniyama district at a scalding 69.9 °C, placing it among Japan's hottest natural sources. The water is colorless and very faintly cloudy at the source, carrying the moderate rotten-egg note of hydrogen sulfide that marks the Kannawa field. It is unusually rich in metasilicic acid at 124 mg/kg, leaving the kind of thin silica film that makes skin feel noticeably smoother afterwards.
pH
4.20
Weakly acidic
Source temperature
69.9°C
Hot
Tonicity
0.39g/kg
Hypotonic
Free CO₂
87mg/kg
Low
Free H₂S
0.40mg/kg
Low
- Color
- colorless, very faintly cloudy
- Taste
- very faintly sour
- Odor
- moderate hydrogen sulfide odor
Highlights
- High silica
- Top-decile hot
Analyzed Sep 21, 2021·公益社団法人 大分県薬剤師会 大分県薬剤師会検査センター·Cert no. 大薬検 第7R-21090009号