Aizome (藍染) Indigo Dyeing Part One

I live in Tokushima Prefecture in Japan. It’s not a well-known place. It’s on Shikoku, the smallest of the four main islands of Japan, and it really only gets well known during the annual four day awa odori festival in August.

It has other claims to fame that the locals are fiercely proud of like sudachi (a citrus fruit) sweet potatoes, whirlpools, and its own version of ramen (which is delicious by the way). But there is one claim to fame that is of particular interest to kimono fans; aizome (藍染) also known as indigo dying.

My home happens to be very close to the local indigo dyeing museum, Ai no Yakata (藍の館). I went there recently to watch a koto concert and I’ve been researching aizome ever since (and dreaming about owning an aizome kimono, but I don’t think my budget can take it!)

This post will be the first in a series of three posts about aizome. In the first post, I will outline the process of creating the dye. In the second part (here), I’ll talk about the actual museum, and in the third part (here) I’ll talk about my experiences in aizome dyeing and some of the benefits of aizome.

The Aizome Process

Begin Japanology has done an incredible video on aizome and I encourage everyone to check it out. It outlines the history of aizome and the process of creating it.

For those of you who don’t want to watch the video (seriously, watch it!) Here’s the process of making aizome.

Aizome uses the fermented leaves of the indigo plant for a dye. The whole point of the long fermentation process to make the compound in indigo plants that is responsible for the colour, indcan, water soluble. The final fermented dye is called sumuko and it can take a year to go from planting the seeds to dyeing the first batch of cloth in the finished product.

The seeds are first planted in March after the threat of frost has subsided. Two months later in May, the seedlings are transplanted into the fields. The mature plants are harvested just after the end of the rainy season in July. The leaves are separated from the stalks and the leaves are dried in the sun. About a month later, a second batch is harvested. This second batch, once it’s been sorted and dried, is stored separately from the first batch to be used in the fermentation process later on.

When it comes to the fermentation process, everything is big, and it takes a long time. I’ve outlined the process to make sukumo below. The information is from an essay written by Isamu Nii, an ai-shi (sukumo maker) that still uses the traditional methods. His essay was published in a book called “Awa No Kusazome; Namida Iro” (The Dye Plants of Awa; The Color of Tears) written by Seiko Akiyama and translated into English by Ann K. Nakamura.


Please note, every step in the process occurs in 5-6 day intervals even when it’s not explicitly stated. 

Ichi-ban mizu (一番水) 1st water application
Approximately 1000 kg of dried indigo leaves are arranged in a pile about one meter high and sprinkled with water.

Ni-ban mizu (二番水 2nd) water application
This occurs about five days after ichi-ban mizu. At this point, the leaves are starting to generate heat and the bacteria are starting to break down the leaves. About 500 kg of the second harvest of indigo leaves are added to the pile. Everything is mixed, sprinkled with water, and piled up to one meter again.

San-ban mizu (三番水) 3rd water application
This occurs 5-6 days later.   Everything is mixed and sprinkled with water.

Yon-ban mizu (四番水) 4th water application
Again, 5-6 days later.   Everything is mixed and sprinkled with water.

Go-ban mizu (五番水) 5th water application
A second batch of 750 kg of dried indigo leaves is added. Everything is mixed and sprinkled with water.

Roku-ban mizu (六番水) 6th water application
A third batch of 750 kg of dried indigo leaves are added. Everything is mixed and sprinkled with water. At this stage, the pile of fermenting indigo is about 3000 kg.

Nana-ban mizu (七番水) 7th water application
This occurs around November.   The temperature drops and the indigo is covered with straw mats called futon to keep it at a constant temperature.

Hachi-ban mizu (八番水) 8th water application
By this stage, the smell of ammonia can be overwhelming.

Kyuu-ban mizu (九番水) 9th water application
Clumps of indigo are broken up at this stage in a process called to-oshi. This ensures that oxygen and moisture are evenly distributed and the indigo is exposed evenly.

Jyuu-ban mizu (十番水) 10th water application
By this point, the indigo is uniformly composted and fermented. The high temperature makes walking over the indigo difficult and the smell of ammonia is overwhelming. Straw bags called kamasu are placed inside the fermenting pile to stop the temperature from going too high.

Jyuu-ichi-ban mizu (十一番水)  Jyuu-ni-ban mizu (十二番水)  Jyuu-san-ban mizu (十三番水)
11th, 12th, and 13th water applications

At this stage, approximately 80 days have passed. The indigo leaves stick to the floor and new straw mats have to be put down to protect the indigo from excess moisture.

Jyuu-yon-ban mizu (十四番水) Jyuu-go-ban mizu (十五番水) Jyuu-roku-ban mizu (十六番水) Jyuu-nana-ban-mizu (十七番水)
14th, 15th, 16th, and 17th water applications

This time is when the experience of the ai-shi really shows. Instinct will tell the sumuko maker when to make the next application of water. He makes his decision based on the amount of water used, the smell, and the temperature of the leaves. When the ammonia smell mellows out, it’s a sign that the indigo has officially become sumuko.

Jyuu-hachi-ban mizu (十八番水)  18th water application
This is the final application. Cold water from underground wells is used. Prayers are said to ensure that the sukumo will give a good colour and sake is sprinkled over it. It’s now the middle of winter and time for the craftsmen to think about planting the next crop in a few months.

completed sumuko

completed sumuko

Now that we have sumuko, we need to make it into the dye. Again, the “Begin Japanology” video does a great job of explaining the process, but here’s a rundown.

The dye’s basic ingredients are sukumo, lime, ash lye, and sake. Everything is mixed in the dye vat and left to settle. It must be kept warm, stirred every day, and examined for signs of fermentation.   Anywhere from three to ten days later, the dye will have started to ferment and will look noticeably different. Large bubbles form that don’t vanish and a metallic sheen covers the top of the dye. At this point, a second batch of lime is added. After a day, the third and final batch is added. The dyer now starts looking for the indigo flower (ai-no-hana 藍の花) to form on the top of the dye. This indicates that they dye is ready to be used.

The completed dye.

The completed dye.


TL;DR? Here’s a short video with the highlights of the process.

That’s all for this post. Check the second installment here.  The third installment is here.


Don’t sweat the small stuff!  But if you’re interested, check out my facebook, twitter, and instagram for the small, spur of the moment ideas, articles, and activities that I find and do related to kimono!


3 thoughts on “Aizome (藍染) Indigo Dyeing Part One

  1. Pingback: Aizome (藍染) Indigo Dyeing Part Two | Ready, Set, Kimono!

  2. Pingback: Aizome (藍染) Indigo Dyeing Part 3 | Ready, Set, Kimono!

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