Dake Onsen

Dake Onsen is unusual in Japan for its acidic water, with a pH of 2.5. The combination of low acidity and sulfur content may offer relief for skin conditions including psoriasis and eczema. The long underground journey from Mt. Tetsu is said to produce especially well-mixed mineral content, referred to as yumomi or kneaded water. Periodically, workers scrape mineral deposits from the supply pipes and let them flow to the baths at once, turning the water milky white. These are announced in advance as Milky Days and happen weekly in summer, less often in winter. Many visitors plan their visit specifically to soak in the clouded, mineral-rich water.