Watanabe Dye House

Continuing on our ongoing journey to discover smaller dyeing Shokunin (craftsmen) in Japan, we had the opportunity to visit the Watanabe Dyeing House based in Tokushima prefecture. Established 13 years ago, Kenta Watanabe and his small team are pioneers in the Natural Indigo dyeing realm.
Sukumo - the key ingredient in producing a natural indigo dye
Bridging the gap between the centuries-old craft of producing this fabled dye and the almost secretive nature of its production has been a mission of Watanabe since starting this operation, and we were lucky to have the opportunity to take a deep dive into the world of Hon-Aizome (Natural Indigo) on this occasion. 


Watanabe’s operation covers the entire scope of producing the natural Sukumo fermented dye, from planting the seeds to producing the Persicaria Tinctoria plants, drying and fermenting the leaves and creating the necessary conditions in the dye baths to yield a dye worthy of producing beautiful hues of Indigo. The geographical location of Tokushima itself is key in creating the precious conditions that are required for the indigo leaves to be grown and harvested each year. Surrounded by rivers running through the region, typhoons and strong rainfall cause the local fields to be flooded annually, enriching the soil with nutrients which yields the high-quality leaves harvested each year. Being that the farming culture is very strong in Tokushima, locals work closely to support one another in a mutual effort to provide long-time benefits to businesses in the long run. Right next door to Watanabe’s we find a pig farm that provides their fields with manure that can be composted and used as fertilizer. Watanabe also comments that fresh produce unfit for supermarkets because of size or shape are redistributed amongst the community and schools to avoid wasting perfectly good food. Furthermore, unused Sukumo is returned to the fields as fertilizer in yet another “zero-waste” initiative held to high regard by Watanabe.
Along with having a harmonious set of farming conditions and location, timing is everything to ensure a smooth annual crop cycle. Plowing, fertilization and planting of the seeds occur during the early winter and spring months from September~April. During the warmer months, the seedlings are transported to the local fields where they are grown and harvested in the summer. Following this, the leaves are separated from the stems and dried in a process known as Aikonashi. Once the separated leaves are collected the fermentation process can then begin in early Winter. Around October, the leaves are laid in a fermentation room on a surface space known as Nedoko (place to sleep) and watered. The watered leaves and ambient air naturally begin the fermentation process which takes around 2 months to complete. The Watanabe craftsmen constantly monitor the conditions of the room and continually add water and mix the piles of leaves ensuring a balanced fermentation process. This constant mixing, ensuring the central leaves come to the outside of the pile - and conversely the outer leaves make it to the center, generates a surprising amount of heat which can be felt when placing your hand on the exterior pile.

Sukumo - unlocking the secrets

A common misconception is that once this fermentation process is completed, the Sukumo is ready to be added to the dye baths in the dye house. However, the Sukumo at this stage is still unstable and unsuitable for fermentation in the vats. As a result, the batches of Sukumo are bagged up and left to further mature for around 6 months. This time is not an absolute however, and Watanabe talks about different “ages” of Sukumo yielding different hues of Indigo, much like how fine wine ages and evolves over time.
Watanabe is also happy to share with us the precious formula required to create the ideal conditions for fermentation in the vats. Along with the Sukumo, alkaline-rich lye is added by mixing wood ash, crushed seashell powder along with wheat bran, which is high in sugar content required for the fermentation of the dye liquid. We sift through pages and pages of hue samples, carefully marked with the dates of which harvest cycle they had been produced in.
At this point, Watanabe comments that despite doing their due diligence in properly controlling the plethora of variables and collecting data, it is important to be forever grateful to nature itself. It is after all, nature itself and the mysterious unknowns that gift them with the treasure that is Natural Indigo, and the spectrum of hues that are cherished around the world.

A bright future for natural indigo

Watanabe Dye House are also at the forefront of making Natural Indigo more understandable to not just Japan, but the rest of the world:

“We don’t aim to simply sell, we want people to try out the whole dyeing process themselves to see what is great about this dye. That is key in people discovering the beauty that natural indigo dyeing results in and an understanding on why it is so expensive.”

Visitors from abroad often visit the dye house, trying out the hand-dye process in the very vats that Watanabe and his team use to dye hundreds of garments each year. Giving it a go ourselves, we were greeted with the almost magical evolution of color throughout the process. From the initial piece of fabric appearing a light green prior to oxidation to the gradual deepening of color over each dye cycle. The real “wow” moment though - is the almost immediate color shift when the dyed garment makes contact with water and is washed, revealing the stunning hue of Indigo.

Looking towards the future, Watanabe continues to expand their farming operations - investing in more land to be used as fields and newer technologies which can make the harvesting and fermentation process more efficient. Currently, a harvest of 1,300KG leaves yields only roughly 10% of that amount in fermented Sukumo. It’s when you realize the sheer scale and tedious nature of the production of this dye, why Watanabe continually invests into the farm. The Watanabe crew also hope to broaden their horizons beyond the farm - taking portable vats to workshops and events to allow people to try out the dyeing process first-hand. While currently this has only been a domestic venture, Watanabe aspires to bring their dyeing experience to other parts of the world in the future.

Special thanks to Watanabe Dye House