As I learned to use organic indigo vats, I started with recipes from Michel Garcia: “one, two, three”. Michel talks about the vats in simple terms. It’s as easy as 1,2,3. This also represents the proportions of indigo, lime, and sugar that go into the vat:

• 1 part indigo
• 2 parts lime
• 3 parts fructose sugar

It’s simple, right?

Not always.

I probably get more questions about making and maintaining an indigo vat than anything else. There are so many unknowns. It’s taken me a number of years to feel comfortable with those unknowns and to gain the confidence to solve problems with the vat.

I recently had several people ask me about the quantity of indigo in the vat. That’s an important question. Unless you know how much indigo, you can’t really determine how much sugar (or other reduction material) or how much lime.

I’ve watched Michel make vats with very small amounts of indigo and what I would consider very large amounts of indigo. What is the difference? Will you get a darker color from a vat with more indigo?

The answer is “yes” and “no”.

I made 3 small fructose vats with varying amounts of indigo

• 2 grams indigo per liter of vat liquid volume
• 5 grams indigo per liter of vat liquid volume
• 8 grams indigo per liter of vat liquid volume

As you can see from the samples dyed the very next day, there was a great deal of difference in the colors produced from each vat. Even on day 3 there was significant difference. But one week later, the 3 shades of blue are much more similar. All of these samples represent only one 20-minute dip in the vat.

Why would you use 8 grams of indigo per liter instead of 2 when you can get a similar color from both these options? There is more indigo in the vat, which means more can be dyed over a longer period of time before additional indigo must be added. If I were doing a short-term vat for a small amount of dyeing, 2 grams of indigo per liter would probably be plenty.

The questions to ask are:

• What  quantity of textiles will  be dyed in the vat?
• How many people will be using the vat?
• How long do you want to keep the vat?
• How quickly to you need to get strong color from the vat?

The coloration of the reduced liquid in the 3 vats is different, indicating varying amounts of indigo in reduction. But the textile is only able to absorb so much dye at a time. We always build up color with multiple, long dips in the vat.

The other thing you can see through these glass jars is the amount of sediment at the bottom of the vat. The weakest vat has very little and it gets progressively deeper with the stronger vats. It’s important to keep our textile above this sediment when it’s dyeing.

I currently have a 30-liter vat that I have been using for over a year now. I’ve added indigo to it a couple of times, and of course plenty of reduction material and lime. The vat is still working well but over the months the sediment has gotten very deep, which has reduced my dyeing space so much that it’s time to make a new vat.

The “1,2,3.. ” proportions are guidelines and easy to measure if you’re using fructose. How many bananas or sweet potatoes do you need to reduce 10 grams of indigo? Take a good guess. Making small experimental vats in glass jars has taught me a great deal about how the vat works. We don’t always know but have to start somewhere.

Observe carefully. One must be patient with the indigo vat.

Michel Garcia has inspired and informed many of us in the use the organic indigo vats. He has given us a simple one, two, three (1:2:3) recipe that refers the proportions of indigo, lime (calcium hydroxide) and reduction material (often a sugar).

But nothing is ever as simple as 1:2:3! Dyers work hard to determine how to keep their vat active, when to add reduction material, when to add  lime, and how to best dye their textiles.

A key issue dyers must think about is the selection of the best reduction material that is also readily available. Michel commonly recommends the use of fructose or a fruit that is high in sugar, such as bananas. These high-sugar materials assure that the indigo vat will go into reduction quickly and successfully. I recently had a reader ask me if dextrose will work as well as fructose. I didn’t know, so I tried it. It was slower to reduce, but in the end resulted in colors very close to those obtained with fructose. On the other hand, cane sugar resulted in no reduction whatsoever.

In November I was in Oaxaca, Mexico for the 10^th Intentional Shibori symposium, where Michel Garcia and I were both teaching workshops. Our time in Mexico proved to be another opportunity to realize how much more there is to learn about indigo vats.

One day, we were eating fresh oranges and Michel mentioned that we could use the orange rinds to reduce an indigo vat. I was surprised (and a bit skeptical) since I knew that oranges were acidic. It turns out that the orange juice is acidic but the rinds are full of pectin, which is an excellent reduction material.  We ate a lot of oranges, cooked the rinds, and used that juice to make our vat. Of course, it worked!

Further discussion of indigo vats in Michel’s class revealed that some vegetables can also be used to reduce the indigo vat: turnips, zucchini, etc. Some of these vegetables contain pectin as well as sugars.

I never really know something until I’ve tried it. In the last few weeks I have made nine small indigo vats using citrus skins and chopped vegetables. I made the vats in glass jars with 1 gram of indigo per liter of solution.  A great deal can be learned about an indigo vat when it’s made in a transparent container. I can see the color of the vat, the amount of un-reduced material at the bottom, and the speed (or slowness) at which the vats reduce. The use of the vat for dyeing is the ultimate test.

The “citrus series” was made with

• Cooked orange rinds
• Cooked lemon rinds
• Commercially available ground orange peel
• Commercially available pectin from the grocery story (additives included dextrose and fumaric acid)

When using fruit, I cooked the rinds from several small oranges or lemons in water and used that liquid as the basis of the vat. I used the 1:2:3 proportions (by weight) as a guideline for the commercially available orange peel and pectin (1 part indigo, 2 parts lime or calcium hydroxide, 3 parts reduction material).

The “vegetable series” was made with

• Zucchini
• Turnip
• Carrot
• Sweet potato
• White potato

I used the equivalent of one medium sized vegetable per liter of vat liquid. The vegetables were chopped into small pieces and boiled for 15-30 minutes or until the vegetable matter was very soft. The liquid was then strained to make the vat.

Every vat worked to some degree. In the “citrus series” both the orange rind vats reduced first, the pectin vat was slow but after a week the color achieved matched the orange rind vats. The lemon rind was the weakest from the beginning and also has a great deal of unreduced material at the bottom. The white potato was the slowest of the vegetables to reduce and the resulting color continued to be the weakest.

Some of these latest experiments were more successful than others but they were a huge revelation for me. There are indigo reduction materials everywhere! Some are better (and more available) than others. I can imagine a new use for the abundance of zucchini in the summer garden and I can use waste from my food kitchen to feed my indigo vat.

Several years ago I was doing indigo dyeing on the Island of St. John in the Virgin Islands. We harvested local Aloe Vera leaves as a reduction material. I later tried reducing a vat with Aloe Vera that was growing in a pot as a houseplant. The houseplant did not reduce the vat.

My studio doesn’t smell as sweet after cooking potatoes and turnips as when cooking orange rinds or bananas (neither does the vat), but it’s another valuable reminder of the complex world of natural dye and the resources at our fingers.

The questions I receive most frequently about natural dyeing seems to center on  the indigo vat and its maintenance. Since 2011 I have been making and using organic indigo vats, an art and  skill that I learned from Michel Garcia.

My current vat began in a 5 gallon vessel over 2 years ago. I enlarged it to fill an 8 gallon vessel, and then last year I enlarged my vat again to fill a 30 gallon container. The increased size was needed because I was dyeing larger pieces of cloth.

The vat was made using henna as a reduction material. I chose to use this material because the slow release of sugars is good for a vat that will be maintained for a long time.  I add fructose after each use and additional henna when I need to boost the reduction. Lime (calcium hydroxide) is the alkaline.

The vat is used regularly and I achieve excellent color from the indigo.  The large size challenges me to solve problems as I encounter them. It would be tempting to discard a small vat that was not behaving well and begin again, but emptying this vat would require a great amount of effort. As a result I’ve learned a lot about maintaining the indigo vat.

An indigo vat is happiest when it is used on a daily basis. After each dyeing session I “feed” it with a bit of fructose, stir it to bring the un-reduced indigo and reduction materials up from the bottom, check the pH, and let it rest for a few hours before dyeing again.

Occasionally I run into problems that I need to solve. Recently I was away from home for several weeks. Before I left, the vat was dyeing rich, deep blues. The color of the vat was a golden bronze and there was a good healthy “metallic” sheen on the surface and plenty of bubbles.

When I returned home the first thing I did was add lime to the vat.  When an indigo vat sits dormant for any amount of time it becomes more acidic and the pH goes down. I can test this with pH papers but a good visual indicator is to sprinkle some lime on top. If the lime is immediately “sucked” down into the vat – you can assume that the vat is in need of the lime. If the lime just sits on the surface, the pH is probably fine.

Next, I stirred the vat and waited for it to settle. The color of the vat looked good, as well as the surface. The vat was a clear gold color and there was a coppery sheen on top. But the first test sample resulted in barely any color at all!  That was a surprise, since I thought there was plenty of indigo in the vat. I thought I had also been “feeding” it with plenty of sugar. The vat had been used very heavily before I went away. I thought that possibly the indigo had finally been exhausted.

Before adding more indigo to the vat, I decided to add more sugar – a generous amount. Once added, the vat was stirred and I waited until the next day to do another test strip. It produced a  blue, though it was relatively light. I repeated the sugar-stir-rest and dyed again the next day. It was darker. I repeated the sequence again, and finally got back to a shade of blue similar to that which I had before going away.

The lesson here is that before adding indigo to a vat, test it thoroughly for pH and reduction.  Although it “appeared” to be healthy, my vat was not reduced and the indigo wasn’t available to dye the fibers.