Introduction of Tenzan no Yu

Flowing Natural Hot Springs

The source flowing from 1200m underground is the first “sodium and calcium chloride spring” in the Kyoto Basin and it has been confirmed that it has high-concentration spring quality (9146ppm) close to seawater (19000pm) which is rare for hot springs located far away from the sea. In addition, it has also been confirmed that those hot springs have chlorine ion concentration (9146ppm) corresponding to 9 times of what is considered as the reference value for medical treatment hot springs (1000ppm), making them medical treatment hot springs having a variety of effects.
In general the term hot spring refers to a spring containing at least 1 component in the 19 kinds of essential substances listed in the Hot Spring Law or containing an existing solvent substance with more concentration than in the specified amount or mineral water/hot water having a temperature superior to 25 degrees. Tenzan no Yu (source) is a natural hot spring which contains 6 essential substances and its temperature is 31.3 degrees Celsius.

Spring Quality Effects (sodium and calcium chloride spring)

The spring quality of this hot spring is called sodium and calcium chloride spring, including sodium ions (3212mg) and calcium ions (912mg) in large quantity. Sodium ions and calcium ions are reacting with the sebum (carboxylic acid) on the surface of the skin and form carboxylic acid, sodium and calcium salt. The sodium carboxylate is a surfactant which has, generally speaking, the same effect than “soap". Its effect penetrates every corner of the skin, removing all impurities and because of its emulsifying effect “moisten” the skin. For in calcium salt there is the same effect than in “baby powder” it will make your skin feel “silky”.

What is carbonated spring...

By dissolving carbonic acid gas (carbon dioxide) in hot water, it creates carbon dioxide water. This carbon dioxide is commonly referred to as carbonated spring, with hot water bubbles adhering to the body when you bathe and is said to be so for 1 kilogram of hot spring water containing 1000mg or more of free carbon dioxide.　
Since carbonated spring is able to improve blood circulation without placing a burden on the heart, is also called a “heart’s hot water” in Germany and is mainly used in Europe as medical hot spring in the treatment of heart disease or hypertension. The best feature of the carbonated spring is that it is working to expand the blood vessels in the skin. When you do carbonated spring bath, the immersed body part turns red in 2-3 minutes and you can clearly see a boundary line with the body part that remained outside. The part which turned red shows that the carbon dioxide penetrated in the blood capillaries and arterioles close to the skin, spread the capillaries and that blood circulation is getting better.

Highly concentrated (1000ppm or more) carbonated spring is recognized as a medical treatment spring and it has been verified even in medical institutions that it procures various effects such as an improvement of blood circulation and an effect on autonomic nerves, etc.

Caution regarding carbonated spring bathing

Concerning the carbonated spring of our shop, we have mixed natural hot spring and artificial carbonate in order to get close to a natural carbonated spring. By using the natural hot springs water of Tenzan no Yu called “Netsu no Yu” (Heat’s hot water) we then create a synergistic effect by making the carbonated spring called “Shinzo no Yu” (Heart’s hot water) increasing even more the thermal effect. In addition, carbonated spring is set 2-3 degrees lower than the normal temperature at 38 degrees. Even though due to the effect of carbonic acid it is still warm enough. Because the temperature of hot water is low, it has the particularity to reduce the burden on the heart and does not make you feel tired even if you stay during a long time. Please enjoy and relax.