Three summers ago, I was cruising the Nashville Farmers Market when I spied Hill and Hollow Farm’s vegetable, flower, and hand-dyed yarn stand. What drew me in was the color blue. Indigo blue.
On that June morning, owner, Robin Verson, was selling Japanese Indigo plants; the plants she uses to make indigo dye for her gorgeous yarns. The yarn is milled from wool shorn from her own flock of Jacob sheep. I wanted in on this exciting blue action. I bought four of her seedlings and planted them that day. By September, the plants looked like this.
As the plants matured to the flowering stage, I was surprised to see there was no blue in sight. The leaves were green, the flowers were pink, and the stems were a bronzy-red. With winter approaching, I left my small crop of indigo to die, in situ. Little did I know how easily they would self-seed here in Tennessee. Three years later, I had a bumper crop of volunteer Japanese Indigo plants.
During the summer, I noticed there were hints of blue on some of the bruised leaves. Hmmm. The color was in the leaves. I read up on how to extract indigo pigment from leaves, and I saw words like alkalization, oxidation, and reduction in the directions. Principles of Chemistry– the only course in college that made me call home crying.
Back I went to the Farmers Market, now three years later, to find Robin to look for the help I needed.
It turns out every summer when Japanese indigo plants are ready for harvest, Robin hosts all-day long indigo workshops at her farm in Breeding, Kentucky. I signed up for a Sunday in late August.
Upon arrival, I immediately fell in love with her farm and her sheep. I wanted both!
Robin explained the steps we were going to go through. Two weeks later, when I went to try it myself, I texted her to ask for a quick cheat-sheet version of the directions. Here is what she wrote: strip leaves, steep in water to 160º (measure water first), alkalinize, oxidize and reduce water, wait for reduction to be complete, dye and send me pictures! Robin had walked us through all these steps with humor and grace … and hospitality; she and her husband, Paul, fed us every step of the way.
Step-by-Step Instructions
1. Harvest and Strip Leaves
Our first job was to strip the basil-like leaves from the 24 pounds of indigo stems harvested that morning. To create the brightest color, the plants are picked just before they start to flower. Once cut, they need to be processed immediately before naturally occurring enzymes in the leaves start to decay the indigo pigment (aka indican).
The black buckets were full of fresh stems, the red baskets held the stripped stems, and the two 80-quart stainless steel pots held the fresh leaves.
2. Make the “Indigo Tea,” aka Dyebath
Robin placed the pots of leaves over propane burners. She poured 12 gallons of tap water into each pot (enough to cover the leaves with water) and lit the burners. The water was heated to 160º over a two-hour period. We used a long compost thermometer to keep track of the temperature.
At 145º you could smell the wilted copper-tinged leaves and see why the dyebath is referred to as “indigo tea.” When the tea was 160º, we cut the heat. We put on heat-resistant gloves and used a short rake to scoop out the leaves and squeeze out as much liquid as possible. The leaves went into the orange compost bucket. The tea stayed in the kettle.
We poured the tea through a sieve to remove dirt and debris.
Robin scooped up a jar of the tea to show us the desired color. The indican molecules had broken down into blueish-indoxyl and sugar.
The indoxyl will not stick to cloth in its current state. It needs to be chemically modified by alkalinizing it with ammonia, oxidizing it with oxygen until it becomes blue-green in color, and reducing it by adding sodium hydrosulfite and allowing it to rest until it becomes neon yellow. Here’s the play by play of that:
3. Alkalinization of the Dyebath
We raised the alkaline level from 7 (the pH of water) to 9 by adding household ammonia at the rate of 2 tablespoons/gallon of liquid used. Some people use baking soda, wood ash, or lye to accomplish this.
4. Oxidation of the Dyebath
Next, we oxidized the dyebath by introducing oxygen in the form of air. We scooped up and poured bucketfuls of dyebath over and over again for 20 minutes to add lots of air bubbles. The liquid turned a deep green-blue. During this process, the indoxyl is transformed into very fine insoluble blue particles. They still won’t stick to fiber in this state, but we’re getting there.
I found this image of workers in Asia adding oxygen to an indoxyl-laden dyebath at http://www.industryofallnations.com/Jeans-At-Industry-Of-All-Nations-ccid_80.aspx.
5. Reduction of the Dyebath
The next step is to reduce the dye molecules in the dyebath. To do this, a reducing agent like sodium hydrosulfite, Spectralite, or Rit Color Remover is added at a rate of 1 tablespoon/gallon of water. Robin had us gently stir in the first two tablespoons of the reducing agent and sprinkle in the rest to not introduce more air. Reducing agents absorb electrons and transform the blue insoluble particles into a neon-yellow color that is now considered in solution. Cover the pot for the two hours it takes the reduction process to happen. The dyebath will look like this when it is ready to dye fibers.
While the mixture reduced, we had lunch. Lunch and dessert were prepared by Robin and her family. The amazing farm-to-table meal was scrumptious. Everyone was gushing. The meal included slow-roasted tomatoes that I loved. Here’s the recipe for them.
Time to Dye!
Before coming to the farm, Robin had asked us to wash the textiles we wanted to dye to remove all dirt and grease. She soaked them in warm water before we dyed them.
The pre-soaked textiles are now added slowly to the warmed dyebath (100-120º). Absolutely no stirring is allowed (to prevent another oxidation). The garments or yarn stay submerged for 15 minutes. It is during this soaking period that the textiles lose their color and become “indigo white” which is in fact, more like “neon-yellow.” The items are removed slowly along the side of the pot to diminish the chance of drips introducing air bubbles.
6. Re-Oxidation
As the textiles are removed, the yellowish indigo particles adhere and penetrate into the fabric’s crevices and transform into insoluble indigo blue as the air mingles with the dye and re-oxidizes it. To intensify the color, let the textiles rest and then redip for another 15 minutes to add more layers of color. Never leave items in the dyebath for more than 15 minutes per dip.
As the re-oxidizing is happening, you’ll see the fibers turn yellow, then green, then green-blue, and ultimately indigo blue. It’s kind of magical.
Give the yarn a bath in clean water and vinegar to set the color and then allow to dry. As an aside, notice the four ties spaced intermittently around each skein of yarn. That’s what keeps yarn from getting tangled while dyeing. In all of my years of knitting, I never considered why those ties were there.
I dyed yarn and this shirt.
I can’t thank Robin enough for her instruction and hospitality while we were with her. I urge anyone interested in learning more about this artform to sign up for one of Robin’s classes next year. You can find her here.
And so what did I do with my crop of indigo? Did I try this at home? You Betcha.
I harvested, weighed, and stripped the leaves, and stewed them in water to 160º.
I removed and strained the leaves, alkalinized the dyebath, oxidated it for 20 minutes, and finally, reduced it for 2 hours in the kitchen sink.
I unwound a ball of yarn, rewound it around a chair, and loosely tied it (so it wouldn’t leave marks), soaked it in the reduced dyebath for 15″, and later, rinsed it in a vinegar and water bath to fix the color.
The results were terrific. I dyed both skeins of blue yarn in the photo, one with indigo dye made at Robin’s workshop using her super fresh indigo leaves and the other, a lighter blue, in my sink using my not so fresh leaves (they had already flowered). I also over-dyed a gray linen shirt I had made for me in India. I love it!
Once you get started and have a sink full of dye, you start searching the house for things that would look good blue. These muslin dish towels painted for me by my beautiful friend, Mary Carter, were dingy and stained. Now they are a pretty indigo blue.
If it wasn’t time for dinner, I would have re-dipped everything to add another layer of color, instead, with a roomful of hungry family looking at me (it was now 6 pm – this took all day!), I opened the drain and let the dye go.
My favorite, most satisfying days are the ones where I get lost in a project and lose all sense of time. Trying my hand at making dye extracted from plants I grew in my yard provided for one of those exciting and memorable days. Please write a comment if you have anything to add to this epic post. I still have so much to learn about growing plants and making natural dyes.
A Good Book
For a good read about the history of indigo farming and dyeing in Colonial America, I suggest, The Indigo Girl, by Natasha Boyd. The book tells the story of Eliza Pinckney, who, as a young, industrious farmer learned to successfully grow indigo in South Carolina. It’s a page-turner.
One last indigo image: the inspiration for this indigo journey started during our trip to India in February. Little did I know, when I took this photo of an IndiGo Airlines bus from our airplane window in New Dehli, how far my curiosity about this rich color would take me.
Related Posts
Making Homemade Plant-Based Dyes
Group Project: A Shibori Dyed Quilt
Morning Rounds in the Garden, July
To Dye For: Making Naturally Dyed Easter Eggs
Learning How to Block Print in Jaipur (India, Part 2)
Shopping for a Saree in South India
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