It is well known that Japanese are the masters in the art of wooden bathtub making. With their beauty, warmth, softness and their multiple properties, they always stand as the highest luxury option for bathrooms. The expression “Hinoki-buro” is commonly used to designate wooden bathtubs, but few people know that the most widely and most ancient material used is the Japanese umbrella pine. In fact, it contains essential oils that have rot-proof properties, which the Japanese Hinoki wood barely has.

The egg-shape model is the latest creation of Koichi Yoshida. When you lay your back on the narrow side and stretch your legs, you have the impression of dipping in a large tub while having great dorsal support. On the wider side, you have more back room, but can enjoy a very comfy cocoon sensation.
Koichi Yoshida is the President of YOSHIDA SHOTEN, which he founded in 1986, transforming his father’s wood shop into an ancient Beni-Hinoki bathtub-making company.

So why do we call wooden bathtubs “Hinoki-Buro”? Koichi Yoshida explains, “The cream of wooden bathtubs is one that is made of Taiwanese ancient red cypress, “Beni-Hinoki.” This wood comes from giant trees that grow up to 25m high with 3 to 4m of diameter, in the highlands of Taiwan, for 1000, sometimes 3000 years.” The lumber of these “Ents” as Tolkien would put it, has been forbidden 30 years ago. However, Yoshida’s father, who owned a wood shop in Kyoto since 1934, had accumulated a reasonable stock before that date. So in 1986, Yoshida transformed his family business into an ancient Beni-Hinoki retailor and started the sales of wooden bathtubs. This material being very expensive from the start and becoming rarer nowadays, there is no surprise when Yoshida confirms that not so many people can afford them. “We can only find Taiwanese ancient Beni-Hinoki here in Japan, now. And we are only a few rare makers.” This wood’s properties are the absolute attributes to bathtub making. First, its shape never changes. Then it contains essential oils that are bactericide and protect from about any known microbe, germs, mould, or viruses. Last comes its aroma…

The Yoshida quality is a pride

The Yoshida quality is a pride: “I have never received any complaints neither been noticed of any defects during my 30-year long career!” Each bathtub is order-made, according to the needs of each customer. Once the material and the design have been defined, Yoshida chooses with his master’s eye the wood he will use. “It has to contain enough essential oil, should not change its shape too much with time, and has to be beautiful to the eye.” The crafting method is based on ancestral workmanship, to which he has added of his own know-how and new ideas along the years. “Nothing is perfect, but we are very close to that!” A bathtub takes 1 to 3 weeks to make, depending on its complexity, and then if the customer wants lacquer, the tub is dismantled and lacquer is added to each piece in 8 layers. “The most important is sanding. If you forget a tiny little detail, you’ll see it right away in the lacquer. You know, what do you see first in beautiful thick black hair? The only white hair!”


1. When the design and material are defined, the wood is meticulously chosen by Yoshida. An ancient Beni-Hinoki plank makes generally 60cm by 4m.

2. The main plank is cut into small pieces that are chiselled, sanded, then assembled together with special glue, to shape a curve or an angle according to the design.

3. Once assembled, the tub is worked with planing, bevelling, and finally extremely precise sanding, which brings all the visual and tactile quality to the tub.

4. The side panels vary in width from 33 to 40mm. Larger edges may give a luxury look, but they don’t affect quality. What differentiates quality: the bottom layered with three planks.

5. Some customers require a lacquered layer. The tub is then dismantled and natural lacquer is added to each part, one layer a day, during 8 days. The type of lacquer that is used keeps the wood breathing and doesn’t affect its bactericidal properties.

6. It is important to keep a few centimeters of space on each side and under the tub, to make it dry faster. Wood lasts well when completely immerged or in all-dry environments. Its only rots when staying for loo long “in-between.” Let’s not forget to wipe the water off after use.
For round-shaped tubs, you use precision guides when chiselling the wood.

Maintenance is easy

The maintenance of a wooden bathtub can seem quite a chore. “It’s a wrong image! As wood is bactericide, you don’t have to use detergents, which on the opposite can deteriorate it with time. People who complain about maintenance are those who neglect their bathtub and are forced 15 years later to re-sand it.” Indeed, since unlike usual bathtubs there is no “dirt line” left after emptying a wooden one, it is very easy to neglect its maintenance, which is in fact very simple: wipe out the water on its surface with a soft cloth after usage. Nothing more. If the room is well ventilated, the bathtub will last for 30 years. When you don’t use it for several weeks, it is preferable to leave a water-full bucket inside to prevent it from over-drying. “But a bathtub that has over-dried, with joints that have loosened, is very easy to repair. You just seal the open creases and that does the trick. It is even rather a good thing, because then you are certain that the wood will no longer change its shape.”



The magic of wooden bathtubs is that you can decide of its shape and let go your imagination! Round, oval, square, angled, they can last up to 30 years indoors or outdoors. Wood is however very sensitive to chlorine, which destroys its natural bactericide properties.

YOSHIDA SHOTEN

1397 Kogacho Ueno, Koga City, Shiga Prefecture

Photography / Tomoya Takai
Interview and text / JQR

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