Eight water types — telling them apart by colour, smell and feel

Only the differences you can feel, no chemistry table needed.

Simple spring

Clear and odourless. Gentle — good for children and older bathers. Hakone-Yumoto, parts of Gero.

Skin feels slippery in the water. The 'beauty bath' family. Gero, Tamatsukuri, Dogo.

Boiled-egg smell, milky white or yellow-green. Tarnishes silver — take jewellery off. Noboribetsu, Manza, Zao, Beppu Myōban.

Tingles; stings cuts. Long soaks irritate skin, so keep it short. Kusatsu, Sukayu.

Lukewarm yet warming; bubbles cling to your body. Nagayu (Oita), Arima Gin-no-Yu.

Strips oil and leaves skin smooth — the 'baking soda' bath. Hirayu, Beppu Kannawa.

Salty. Keeps you warm long after — you may keep sweating. Wakura, Atami, Ibusuki.

Turns rust-red on contact with air; stains towels. Arima Kin-no-Yu, Ikaho.

Clear and ordinary-looking. Tradition is repeated dips in lukewarm water. Misasa, Arima.