Yachi Onsen No. 1 Spring
Analysis UnverifiedSaid to have been in use for some 400 years and known as a healing retreat since the Edo period, this spring below the Hakkoda Mountains rises directly through the wooden floor of the "lower bath," long called a sacred 38-degree spring. At 37.0°C it sits close to body temperature, carrying a strong sulfur aroma and white mineral flakes, with bubbles popping at the drinking spout — water meant for long, quiet soaks.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
The aroma typical of sulfur springs, with circulatory and antibacterial effects.
Absorbed through the skin to gently promote peripheral circulation.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
▸Note
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
Close to body temperature, this water suits slow soaks of 30 minutes or more. On cool mornings and evenings, alternate with the hotter upper bath to avoid getting chilled, and mind ventilation given the strong hydrogen sulfide.
With 2.8 mg/kg of free hydrogen sulfide, this sulfur spring has long been valued as a skin bath and is traditionally associated with immune system stimulation, while its mildly acidic pH 4.62 tightens the skin toward a silky skin finish.
The hydrogen sulfide is strong, so keep the bathhouse ventilated and leave if you feel unwell; sulfur may discolor metal jewelry, and sensitive skin may benefit from a rinse afterward.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Yachi Onsen No. 1 Spring
- Spring type
- Simple Sulfur Hot Spring (hydrogen sulfide type)
- Source temperature
- 37℃
- pH
- 4.62
- Flow type
- 自然湧出
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2025-06-20
- Analyst organization
- 一般財団法人 青森県薬剤師会 食と水の検査センター
- Registration No.
- 青森県第2号
Cations
- Lithium ion Li⁺
- 0.00 mg/kg
- Sodium ion Na⁺
- 40.3 mg/kg
- Potassium ion K⁺
- 5.2 mg/kg
- Ammonium ion NH₄⁺
- 0.00 mg/kg
- Magnesium ion Mg²⁺
- 17.2 mg/kg
- Calcium ion Ca²⁺
- 109 mg/kg
- Aluminum ion Al³⁺
- 0.20 mg/kg
- Manganese ion Mn²⁺
- 0.60 mg/kg
- Iron(II) ion Fe²⁺
- 0.00 mg/kg
- Zinc ion Zn²⁺
- 0.05 mg/kg
- Lead ion Pb²⁺
- < 0.01 mg/kg
- Copper ion Cu²⁺
- < 0.01 mg/kg
- Cadmium ion Cd²⁺
- < 0.005 mg/kg
- Total cations
- 0.17 mg/kg
Anions
- Fluoride ion F⁻
- 0.20 mg/kg
- Chloride ion Cl⁻
- 9.1 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.00 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.20 mg/kg
- Sulfate ion SO₄²⁻
- 426 mg/kg
- Bicarbonate ion HCO₃⁻
- 5.5 mg/kg
- Carbonate ion CO₃²⁻
- 0.00 mg/kg
- Bromide ion Br⁻
- 0.00 mg/kg
- Iodide ion I⁻
- 0.00 mg/kg
- Hydrogen sulfate HSO₄⁻
- 0.30 mg/kg
- Dihydrogen phosphate H₂PO₄⁻
- 0.00 mg/kg
- Sulfide ion S²⁻
- 0.00 mg/kg
- Total anions
- 0.44 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 0.00 mg/kg
- Metasilicic acid H₂SiO₃
- 32.4 mg/kg
- Metaboric acid HBO₂
- 1.0 mg/kg
- Total undissociated
- 0.03 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 107 mg/kg
- Free hydrogen sulfide H₂S
- 2.8 mg/kg
- Total dissolved gas
- 0.11 mg/kg
Totals
- Total dissolved substances
- 0.65 mg/kg
- Component total
- 0.76 mg/kg
- Evaporation residue
- 0.65 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Atopic dermatitis, Plaque psoriasis, Chronic eczema, Epidermal suppuration
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Depression, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
- Contraindications
- Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages), Severe chronic dermatitis (sulphur springs)
Drinking
- Drinkability
- Not drinkable
