つぼ湯
Tsubo-yuOperated by · 田辺市四村川財産区
- Color
- colorless and transparent
- Taste
- weakly sulfur
- Odor
- weak hydrogen sulfide
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.
- Skin conditionsatopic skin, eczema
- Circulationtired legs
- Aches & jointsstiff shoulders
- Sensitive-skin cautionbroken or dry skin
Named simply after the cave-bath itself, Tsubo-yu is a sulfur-bearing sodium bicarbonate-chloride spring — the soft, skin-smoothing 'jūsō-sen' bicarbonate frame layered with a salty, heat-retaining chloride finish, all carried on a quiet H₂S note. At pH 6.9 it sits in neutral territory; the water emerges colourless with a faint rotten-egg whisper and a mild sulfur taste on the lips. Metasilicic acid is generous at 95.5 mg/kg, leaving the kind of fine silica film that makes skin feel noticeably smoother afterwards. The source rises naturally at 53.5 °C and feeds the small rock-pool tub that gives the spring its name along the Kumano Kodō pilgrim route.
Sampled at wellhead·Analyzed Mar 20, 2015·一般社団法人 和歌山県薬剤師会 医薬品・公衆衛生検査センター·Cert no. G1502080号