A Bath in the Mountains of Nagano

The Japanese onsen tradition is, among other things, a five-hundred-year argument against the modern soap aisle. You sit on a low wooden stool in the washing room. You scrub yourself clean with a coarse cotton cloth and a single bar of plain soap. You rinse. Only then are you permitted into the hot mineral bath. There is no body wash, no exfoliating gel, no aromatherapy, no fourteen-step routine.

The bar, in the better ryokan, is hinoki — Japanese cypress. The fragrance is not added. It is steam-extracted from the heartwood of trees that grow on the slopes around the bath, and folded into a base of pure rice-bran oil and lye. Nothing else. A good hinoki bar smells like a forest just after rain, with a faintly sweet woody note underneath that the Japanese call yūkon, roughly: the deep root.

What strikes a Western soap maker, after a week of bathing this way, is how badly we have over-engineered the experience of getting clean. A real hinoki bar is one ingredient for fragrance, one ingredient for fat, one ingredient for saponification. Three things. The bar costs the equivalent of about four dollars, lasts a month, and leaves your skin smelling like the inside of a temple.

We are not going to make a hinoki bar. The cypress essential oil is too expensive to ship at our price point, and frankly the Japanese do it better than we ever could. But we took two ideas home from Nagano: that a single, honest fragrance ingredient will always beat a complex synthetic blend, and that there is dignity in a soap that knows it is a soap and not a beauty product.

Our Norse Viking bar uses one fragrance ingredient: birch tar. Our forthcoming Apache bar will use one: wild desert sage. The Aleppo bar uses none — the laurel oil is the smell. This is not minimalism for its own sake. It is, we think, the lesson of the onsen.

— Filed from Nagano, Japan