Sukumo (すくも) fermented indigo leaves

This is a photo of the indigo plant most commonly used in Japan. It is a member of the buckwheat family and called tade ai (タデ藍）in Japanese. the scientific name is Polygonum tinctorum. The flowers can be either pink or white and don't effect the color of the indigo. If you pinch the leaf it will turn blue where it's bruised. The leaves can be used either fresh or dried to get a light blue or light turquoise, and also pinks and purples on silk fabrics under certain conditions but these colors are not stable. To get the faster dark indigo blue you must have an oxygen free vat and repeatedly submerse and then oxidize your fiber.

The following photographs are from a Japanese homepage called Seirantei (青藍庭 which literally translates to 'Blue Indigo Garden'), a sukumo making company in Tokushima which is basically the center for indigo in Japan. There are some beautiful pictures throughout the page and it's definately worth a look at.
http://www6.ocn.ne.jp/~seiran1/index.htm

Here you can see the leaves in the field tinged with blue.

Sukumo is the composted leaves you start your vat with. The 40 liter vat I made uses 2 kg of sukumo. I use around 8 kg in the pots I normally deal with. To make the sukumo the leaves are collected and piled in a traditional wood and mud wall barn (kura/蔵) with a dirt floor and sprinkled with water and lime. As the leaves begin to compost they generate heat.

Here the compost is covered with burlap.

The leaves are turned over everyday and continually sprinkled with water and lime to induce the fermentation. It is a hot and steamy, very labor intensive job to keep these leaves composting properly. It also has a quite intensly organic fragrance.

This process is different from the extraction process most commonly used in India where the fresh leaves are fermented in a high alkili solution to dissolve the indican and then stirred or beaten or actually run around in by laborers to oxidize the liquid which is then allowed to settle, the top liquid discarded, and the end sludge collected as pigment which can then be used in a reduction vat for dyeing.

40 liter Vat, Day 23 (Why Stir?)

rainy 20C / 60%
28C / ph11.2

smells more of ammonia again

Dyed 110x40(centimeter) linen
(guntai shibori) 5min / 2x

1 1/4 cup lime solution after dying

-The color sample swatch-

We hold a small piece of thin cotton fabric just under the surface of the dye for 30 seconds and rinse it immediately. This is done daily, when we also check temp and ph before dying and/or stirring. It's a helpful record to keep so you can see from day to day how the color is changing and also for future reference.

-The surface after stirred. (after dying)-

The vat must be stirred every day regardless of whether you dye with it or not. The bacteria needs oxygen to breathe in order to maintain healthy fermentation. If you do not stir it the bacteria will suffocate and your vat will die, leaving you with a bunch of smelly brown liquid. The idea is to bring the sludgy fermented leaf matter up from the bottom in a circular motion aerating and releasing the oxygen which forms bubbles on the surface called 'ai no hana' in Japanese. A good stirrer and a healthy pot will generate a nicely dome-shaped round of uniformed bubbles in the very center of the pot. As I stated earlier, square is hard to stir. We end up with a kind of deflated mass. This photo also shows the small, milky, greenish foam around our mis-shaped ai no hana. This sort of foam is not ideal. It shows a young vat that is fermenting a little too quickly. The 'hana' itself should have bigger bubbles and not look this foamy. The ammonia smell is also the sign of a newly fermenting vat. We were happy to have that smell when we were first setting up the pot but it should not be so strong at this stage. We added a cup more of the lime solution than we normally would after a dying session.

Analog Indigo Diary

This is our Indigo Diary for the 40 liter vat. We record what we do to the vat each day, the ph level, temperature, the smell if it's distinct or important, and a color sample swatch. We are also recording the size and weight of fabric we dye along with before and after swatches to see if, when we set up '40 liter vat II' we can be consistant with this kit idea.

We started the journal on May 5th like this;

Day 1: tsukumo (2kg), lime#1(from kit), bran#1, #2 ash water(ph10.1) 65C, 20 liters

Mashed tsukumo to fine, thick paste (1 1/2 hours)

Put into heated bucket, electric blanket set to '5'

When finished--45C/ph10.3 smells like organic fertilizer

The photograph shows pages 4&5 from April 19 through today. We started dying on the 22nd and planned to use the pot every other day but today's sample was still a little weak so we put it off.

Today's journal reads;
4/26. 17C/45%. (This is the temp and humidity inside the barn which houses the indigo vats)
11.6/28C (This is the ph level and temp (celcius) of the vat)

Stirred.

In the sample swatches I think you can see how the color changes. The first swatch on the left hand page, is the day before we dyed the bandana and a 1meter square piece of fabric. The sample of the fabric shows the color after 2 dips of 6 minutes each with an oxidation time of 10 minutes between dips. That darkest swatch two days later (on the right hand page) is after dying that same fabric 3 more times. The following day our color sample was quite pale and splotchy. In a bigger vat the reaction would not be so drastic. I am used to working with vats about 5 times this size so was a little surprised. Today's sample is much better. Still not as dark as the very first sample but a brighter, more clear color. I think we can dye tomorrow.

Lye from Ash

These jars contain wood ash from various sources and are being tested for alkalinity. High alkaline ash water is the base for a traditional Japanese fermentation vat. No matter where you are or what kind of indigo you are using, a high alkaline, oxygen free atmosphere is essential. These conditions can be met in various natural or synthetic chemical ways and they all have their advocates. I like the natural fermentation way for several reasons and one of them is I have access to good quality ash left after potter friends fire their kilns. I couldn't reason burning down a specific kind of tree just for my dye pot so even though it is not the traditionally preferred kind it is doing it's job well.

It is the fermentation in a fermentation vat that causes the loss of oxygen(reduction). The high alkali from the wood ash dissolves the normally insoluble indigo making it lose an oxygen molecule. In this state it is colorless and called 'indigo white'. When you lower what you want to dye into the vat the indigo attaches itself to the fibers and when you lift it out oxygen from the air re-attaches itself to the indigo, oxidizing it, which causes the fabric to turn blue right before your very eyes. It can make you feel a little like an alchemist, or a witch, and this is when, if you are going to get bit by the bug, you will.

I make my ash water by putting the ash into a bucket, filling it up with hot water and stirring it everyday for a week. The ph level varies according to the type of wood and how it was burned and apparently other things. The highest ph level I ever got from wood ash was 13. I am working now with 10.8 but my 40 liter vat is maintaining at 11.4 and doing great.

I heard at one point that bacteria in the ash aids the fermentation process but I have never read that anywhere. I have read that the bacteria in the dye root madder, added to some vats in India, does help.

The 40 liter Fermentation Vat

We started the 40liter vat in response to several requests for directions on how to make a small natural fermentation vat, and as a kind of challenge to the notion held by several lovely indigo teachers I know that you cannot give a successful 'recipe' for making an aigame because there are too many outside factors which influence the outcome and that only experience can teach how much of what to add and when. I feel you need to start somewhere and if there is not an expert indigo dye teacher in the neighborhood you can apprentice yourself to why not try a 40 liter vat 'recipe' that reads like my mom's directions to the store; way too many landmark descriptions and a lot of  'if you see that you've gone too far' type of warnings.

The vat I am currently showcasing in this blog is my first test of this idea and I already noticed a small mistake in calculating, discovered a flaw in what I thought was a brilliant idea for not making the liquid in such a small container too sludgy, and realized that square is hard to stir. (More on these things in upcoming posts.)

So, saying that, I have a small number of 'kits' available (basically for the price of supplies and shipping) that I would love for some anal indigo challengers to test and keep track of with daily records so we can check this out.

The 'ingredients' are packaged in such a way that you don't need to do any measuring or weighing. The theory is one can just add the ingredients in order (they are numbered) when the condition of the pot looks (compared to photos), tests (ph & temp), and smells (by apt descriptions) the way it should at a given stage.

The above pic shows the basic kit idea;

-Tskumo, or composted indigo leaves (center), hard wood ash (between 3 & 6 o'clock) and then 4 small packs containing appropriate measures of lime and red wheat bran for the 3 stages of 'Beginning, Middle and Stop' plus enough for general maintenance that should fully cover the life of your vat. (Sounds better than the guarantee on my new drill.)

Next up; Making the alkili solution and why you need to

40 liter Vat's First Dye

Moe, an artist who sells her handmade cards at our shop, came from Tokyo to visit Tereya and decided to try dying. We used the 40 liter vat for the first time.

She tied knots in the 4 corners and the

center of a cotton square.

This took about 1 1/2 minutes.

After wetting out the fabric she lowered it into the dye vat.

She kept the cloth under the surface and moved it around for 4 minutes

then brought it out into the air to oxidize for 10 minutes and then repeated this.

After oxidizing for the 2nd time she opened the center knot,

dyed the cloth one more time for 2 minutes, oxidized and then rinsed it.

She ended up with this lovely bandanna.

Not bad for a first try.

Alternative Aigame-s (and semantics)

This is the 40 liter (10.5 gal) indigo vat. The one in the first post  holds 270 liters (71 gal). Besides the size you may have noticed a few other differences.
I hesitate, in a way, to call a 40 liter plastic pail an 'aigame' but I do anyway.
The plastic bucket is more common these days but whatever sort of container, it can be called 'aigame' if it is used for indigo. Since Indigo needs to be either fermented or reduced chemically, to produce that dark blue, buckets full of indigo are usually called 'vats' in English.
Our mini 40 liter aigame is a natural fermentation vat which was started 2 weeks ago. It is wrapped in an electric blanket, insulated and then covered with an old drop cloth, giving it a kind of trendy grunge look. The temperature must be maintained at around 27C or else the bacteria will become sluggish and hibernate. The ph level must be very alkaline in order to dissolve the indican pigment, making it useable as a dye.