Nyuto no Yu
Analysis UnverifiedThis spring rises on a plateau wrapped in old-growth beech forest at the foot of Mt. Akita-Komagatake, the gateway to Nyuto Onsen. Unlike the milky sulfur springs that dominate the area, it is a brownish bicarbonate water that leaves the skin slippery and smooth, with a faint tart taste and a hint of iron. It is warmed in the deep-snow winter months, and invites a side-by-side comparison with the area's white sulfur waters while you take in fresh green or autumn leaves.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A "beauty spring" that gently emulsifies dead skin cells, leaving skin smooth after bathing.
A trace component with gentle antibacterial and anti-inflammatory action.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
Transdermal absorption gently supports skin hydration and muscle relaxation.
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.
At a neutral pH 6.9 the water is gentle for long soaks; to keep the smooth feel, avoid over-rinsing afterward and moisturize.
With 1,541 mg/kg of bicarbonate softening surface skin and oils, this "beauty spring" may support silky skin, while its neutral, gentle feel lends itself to deep relaxation and a light, refreshed finish.
Avoid lightheadedness from long soaks and drink water before and after bathing.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Nyuto no Yu
- Spring type
- Sodium Bicarbonate Hot Spring
- Source temperature
- 49.5℃
- pH
- 6.9
Analysis Document
- Analysis date
- 2023-11-30
- Analyst organization
- 株式会社 秋田県分析化学センター
- Registration No.
- 秋田県第2号
Cations
- Lithium ion Li⁺
- 0.20 mg/kg
- Sodium ion Na⁺
- 480 mg/kg
- Potassium ion K⁺
- 16.6 mg/kg
- Ammonium ion NH₄⁺
- 5.2 mg/kg
- Magnesium ion Mg²⁺
- 48.3 mg/kg
- Calcium ion Ca²⁺
- 56.4 mg/kg
- Aluminum ion Al³⁺
- < 0.1 mg/kg
- Manganese ion Mn²⁺
- 0.10 mg/kg
- Iron(II) ion Fe²⁺
- 0.40 mg/kg
- Iron(III) ion Fe³⁺
- 0.70 mg/kg
- Zinc ion Zn²⁺
- < 0.1 mg/kg
- Lead ion Pb²⁺
- < 0.05 mg/kg
- Strontium ion Sr²⁺
- 0.50 mg/kg
- Barium ion Ba²⁺
- 0.10 mg/kg
- Copper ion Cu²⁺
- < 0.1 mg/kg
- Cadmium ion Cd²⁺
- < 0.005 mg/kg
- Total cations
- 0.61 mg/kg
Anions
- Fluoride ion F⁻
- 0.80 mg/kg
- Chloride ion Cl⁻
- 44.5 mg/kg
- Hydroxide ion OH⁻
- < 0.1 mg/kg
- Hydrogen sulfide ion HS⁻
- < 0.1 mg/kg
- Thiosulfate ion S₂O₃²⁻
- < 0.1 mg/kg
- Sulfate ion SO₄²⁻
- 90.3 mg/kg
- Bicarbonate ion HCO₃⁻
- 1541 mg/kg
- Bromide ion Br⁻
- 0.30 mg/kg
- Iodide ion I⁻
- 0.20 mg/kg
- Nitrate ion NO₃⁻
- 0.10 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 1.6 mg/kg
- Total anions
- 1.7 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- < 0.1 mg/kg
- Arsenious acid HAsO₂
- < 0.1 mg/kg
- Metasilicic acid H₂SiO₃
- 148 mg/kg
- Metaboric acid HBO₂
- 25.1 mg/kg
- Total undissociated
- 0.17 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 116 mg/kg
- Free hydrogen sulfide H₂S
- < 0.1 mg/kg
- Total dissolved gas
- 0.12 mg/kg
Totals
- Total dissolved substances
- 2.5 mg/kg
- Component total
- 2.6 mg/kg
Usage
- Heating
- Yes（乳頭の湯の館内掲示（R5.11.30分析書の別掲『成分に影響を与える項目』、湯活のススメ 2025-09-10撮影）『冬期間は浴槽温度が低いため、加温しています』。）
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Cuts and grazes, Peripheral circulatory failure, Poor circulation, Xeroderma
- 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)
Drinking
- Drinkability
- Not drinkable
