Yusai no Yado Bokai Honkan
Analysis VerifiedThis private source gushes in the Kitahama district, part of Japan's premier onsen resort, Beppu, overlooking the bay. Located in an area that has long flourished as an entertainment district, this spring has soothed countless travelers. Combining the qualities of a bicarbonate and a chloride spring, its waters gently exfoliate the skin while a veil of salt locks in moisture. After bathing, you can enjoy a unique texture that is both silky and deeply hydrated. It is a renowned spring perfect for releasing mind and body while feeling the Beppu sea breeze.
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.
- Chloride (salt)144 mg/kg
- Feel
- Tastes salty; the warmth lasts after you get out.
- Said to
- Salt is said to form a film on the skin that keeps in heat and moisture. Bathing indications include cuts, poor circulation and dry skin.
- Note
- May sting cuts. Strong salty water can tire you—avoid long soaks.
- Bicarbonate (baking soda)442 mg/kg
- Feel
- Your skin feels smooth and silky.
- Said to
- Said to remove old skin cells and excess sebum. Bathing indications include cuts, poor circulation and dry skin.
- Note
- It can leave skin dry—moisturize after bathing.
- Metasilicic acid234 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 temperature56.3℃
- 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 gentle pH of 8.3, this weakly alkaline water is kind to the skin, but avoid prolonged soaking. Start with a 5-10 minute dip to acclimate your body, taking breaks between soaks. The chloride components create a warming veil on the skin; for lasting effect, lightly pat dry after bathing without rinsing off.
Rich in bicarbonate ions (442 mg/kg), this spring offers a cleansing effect that emulsifies and washes away old skin cells, making it ideal for achieving silky skin. Additionally, chloride ions form a thin veil on the skin, providing restorative warmth that prevents post-bath chills. With 234 mg/kg of metasilicic acid to help maintain skin moisture, it's also recommended for balneotherapy during dry seasons.
Indications and contraindications are listed on a separate sheet. Generally, individuals with active tuberculosis, malignant tumors, severe heart disease, or those in early or late pregnancy should avoid bathing. If you have health concerns, please consult a doctor beforehand.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Yusai no Yado Bokai Honkan
- Spring type
- Sodium Bicarbonate and Chloride Hot Spring
- Old spring type name
- 含食塩－重曹泉
- Source temperature
- 56.3℃
- pH
- 8.3
- Flow type
- 動力揚湯
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2025-01-15
- 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⁺
- 0.60 mg/kg
- Sodium ion Na⁺
- 273 mg/kg
- Potassium ion K⁺
- 42.1 mg/kg
- Ammonium ion NH₄⁺
- 0.30 mg/kg
- Magnesium ion Mg²⁺
- 1.8 mg/kg
- Calcium ion Ca²⁺
- 8.7 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
- 327 mg/kg
Anions
- Fluoride ion F⁻
- 0.20 mg/kg
- Chloride ion Cl⁻
- 144 mg/kg
- Sulfate ion SO₄²⁻
- 88.5 mg/kg
- Bicarbonate ion HCO₃⁻
- 442 mg/kg
- Carbonate ion CO₃²⁻
- 18.0 mg/kg
- Bromide ion Br⁻
- 0.40 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 0.50 mg/kg
- Total anions
- 694 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 0.00 mg/kg
- Phosphoric acid H₃PO₄
- 0.00 mg/kg
- Arsenious acid HAsO₂
- 0.40 mg/kg
- Metasilicic acid H₂SiO₃
- 234 mg/kg
- Metaboric acid HBO₂
- 7.1 mg/kg
- Total undissociated
- 242 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
- 1262 mg/kg
- Component total
- 1262 mg/kg
- Evaporation residue
- 951 mg/kg
Usage
- Heating
- No
- Dilution
- Yes
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Cuts and grazes, Peripheral circulatory failure, Poor circulation, Xeroderma, Depression
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, 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
