Onsen: Benefits of Alkaline and Acidic Hot Springs
Have you ever heard that in Japan there are five types of “Onsen (温泉)” hot springs that were defined based on pH values by Japan’s Ministry of Environment?
For those who don’t know about this, first of all, they are as follows.
| pH values | Types of Onsen |
|---|---|
| pH8.5 or above | Alkaline Onsen |
| pH7.5 to pH8.5 | Weak Alkaline Onsen |
| pH6.0 to pH7.5 | Neutral Onsen |
| pH3.0 to pH6.0 | Weak Acidic Onsen |
| pH2.0 to pH3.0 | Acidic Onsen |
Benefits of Alkaline and Acidic Onsen
Each Onsen listed above has its own characteristic properties, but today I will just talk about the difference in benefits between alkaline and acidic hot springs.
Now, let’s get started with Alkaline Onsen.
Alkaline Onsen (pH7.5 or above)
In addition to dissolving sebum on the surface of the skin, alkaline hot spring water softens keratin so it can smoothen skin texture.
For that reason, many alkaline Onsen hot springs in Japan are called “Bijin no Yu (美人の湯)” loosely meaning “Hot spring for making you more beautiful”
However, if the pH value of an alkaline hot spring is quite high, that can cause dryness of the skin.
Therefore, after you soak in a strong alkaline Onsen bath, it is better to have a shower in order to wash away components from the hot spring water.
Acidic Onsen (pH2.0 to pH6.0)
Tamagawa Onsen (玉川温泉)
On the other hand, Onsen with low pH values has strong sterilizing power so it may give your skin some tingling sensation. But the acidic water is especially effective for chronic skin diseases such as athlete’s foot.
However, soaking in a quite strong acidic Onsen bath can cause rough skin. Therefore, as with the case of Alkaline Onsen, after bathing, it is better for you to have a shower in order to remove its components from your body.
By the way, speaking of acidic Onsen, Tamagawa Onsen, a hot spring resort in Akita Prefecture, is especially famous.
(Reference Page: tenseien.co.jp)
