Yufuin Sansuikan Asagiri no Yu
Analysis VerifiedAs its name "Asagiri no Yu" (Morning Mist Bath) suggests, this source gushes forth in a location overlooking the Yufuin Basin's magical morning mist. It is a private source nurtured by one of Yufuin's most historic establishments, founded in 1911. The alkaline simple spring is gentle on the skin. Its abundant metasilicic acid helps to wash away old skin cells, leaving your skin feeling silky smooth. It is a renowned spring perfect for days when you wish to quietly reset your mind and body at the foot of Mt. Yufu.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
A trace component with gentle antibacterial and anti-inflammatory action.
- Alkaline (pH)pH 8.5
- Feel
- Feels slippery and silky on the skin.
- Said to
- Said to remove old skin cells and excess sebum.
- Note
- Skin can dry out afterwards—moisturize after bathing.
- Metasilicic acid254 mg/kg
- Feel
- Your skin may feel smoother.
- Said to
- 50 mg/kg or more is said to mark a “skin-beautifying spring”; it is also used in skincare.
- Note
- The “skin-beautifying” label is a common rule of thumb, not a legal standard.
- Source temperature64℃
- Feel
- The source is 42°C or hotter; the bath may be on the hot side.
- Said to
- Heat is said to boost circulation and warm the body.
- Note
- Older people and those with high blood pressure or heart conditions should avoid baths of 42°C or more. Keep soaks short.
Effects are general descriptions based on the Ministry of the Environment’s indications by spring type, not a guarantee.
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.
With a pH of 8.5, this alkaline simple spring is gentle enough for longer soaks. Immersing yourself slowly in the lukewarm water allows its rich skin-beautifying components to penetrate more easily. For best results, avoid rinsing off with a shower after your bath to let the minerals remain on your skin.
With a pH of 8.5 and a high metasilicic acid content of 254.0 mg/kg, this spring is truly for achieving "silky skin." It is known to gently remove old skin cells and refine skin texture. Its low-irritant qualities also make it ideal for balneotherapy on days when you seek to unwind, inviting a sense of deep relaxation.
While the spring is gentle, please be aware of the general contraindications for all onsen, such as active illnesses or severe heart conditions. Refrain from bathing if you are unwell, and avoid excessively long or frequent soaks.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Yufuin Sansuikan Asagiri no Yu
- Spring type
- Alkaline Simple Hot Spring
- Old spring type name
- 単純温泉
- Source temperature
- 64℃
- pH
- 8.5
- Flow type
- 動力揚湯
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2021-05-26
- Analyst organization
- 公益社団法人大分県薬剤師会
- Registration No.
- 大分県第3号
Cations
- Lithium ion Li⁺
- 0.30 mg/kg
- Sodium ion Na⁺
- 138 mg/kg
- Potassium ion K⁺
- 21.4 mg/kg
- Calcium ion Ca²⁺
- 1.3 mg/kg
- Lead ion Pb²⁺
- < 0.01 mg/kg
- Copper ion Cu²⁺
- < 0.05 mg/kg
- Cadmium ion Cd²⁺
- < 0.001 mg/kg
- Total cations
- 161 mg/kg
Anions
- Fluoride ion F⁻
- 0.20 mg/kg
- Chloride ion Cl⁻
- 85.1 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.20 mg/kg
- Sulfate ion SO₄²⁻
- 31.8 mg/kg
- Bicarbonate ion HCO₃⁻
- 203 mg/kg
- Carbonate ion CO₃²⁻
- 7.2 mg/kg
- Bromide ion Br⁻
- 0.20 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 1.1 mg/kg
- Total anions
- 329 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 0.00 mg/kg
- Phosphoric acid H₃PO₄
- 0.00 mg/kg
- Arsenious acid HAsO₂
- 0.00 mg/kg
- Metasilicic acid H₂SiO₃
- 254 mg/kg
- Metaboric acid HBO₂
- 4.1 mg/kg
- Total undissociated
- 258 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- < 0.1 mg/kg
- Free hydrogen sulfide H₂S
- 0.00 mg/kg
- Total dissolved gas
- 0.00 mg/kg
Trace Components
- Radon Rn
- < 7.4 Bq/kg
Totals
- Total dissolved substances
- 748 mg/kg
- Component total
- 748 mg/kg
- Evaporation residue
- 603 mg/kg
Usage
- Usage status
- Unknown
Indications & Contraindications
- Bathing indications
- Autonomic instability, Insomnia, Depression
- General indications
- High blood pressure (mild), Rheumatoid arthritis, 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
