Kneaded Water and Milky Days at Dake Onsen
The waters at Dake Onsen are acidic, with a pH of 2.5. This is rare in Japan, where most hot springs are alkaline. The antibacterial effect of the low pH combined with the water’s sulfur content means that soaking in the springs may offer relief from psoriasis, eczema, and skin inflammation.
Onsen connoisseurs believe that the water’s long journey from Mt. Tetsu mixes its mineral content more evenly, making it feel “smoother” on the skin. This kind of mixing is referred to as yumomi, or “kneading the water,” and is also practiced at other hot-spring resorts in Japan.
Milky Days
The pipes that deliver the waters of Dake Onsen from their source on Mt. Tetsu gradually become encrusted with deposits of sulfur and other minerals in the spring water. These deposits are known as yu no hana or “hot-spring flowers.” To ensure that the flow of water remains unimpeded, the pipes are regularly cleaned by scraping off these deposits, allowing the flakes to flow down the pipes all at once. When the accumulated yu no hana of a week or more arrives at Dake Onsen, it turns the baths milky white for the day. Dake Onsen now promotes these events as “Milky Days.”
Milky Days occur weekly in summer and about half as often in winter. The specific dates depend on when the weather permits cleaning, but they are announced online in advance. Many visitors make a point of visiting Dake Onsen on Milky Days to enjoy the distinct texture and rich scent of the yu no hana. Some feel that the additional mineral content enhances the water’s soothing properties.
