19 March 2014

fermenting indigo the natural way

For many years, I was happy and content dyeing with plants found practically under my feet. Sometimes, when studying dusty old dyeing books, I saw intimidating indigo recipes, which required purchase and use of chemicals I couldn't pronounce, and even less understand the effects and consequences of. So I didn't make blues, even though it's a favourite colour of mine. But didn't care that much, really, there's a big world of colours, besides blue.

There's a time for everything. The blues started growing in my own garden, and then I just had to go with the flow. A new world  opened up to me through the japanese indigo, and now I've even begun flirting with the 'real thing'. There are - and has been, for generations and generations - ways of fermenting indigo, that are not harmful to the environment. It's like fermenting food, just a tad more smelly

Above is a vat I started approximately 2 weeks ago, and since then it has come alive and developed a copper film on top of the vat, standing on the warm bench of our mass oven. The recipe is from here; and it goes as follows:

· 50 grams of finely ground indigo

· 28 grams finely ground madder root

· 28 grams regular old wheat bran (I made it by milling and sifting some grain of wheat)

· 170 grams washing soda

After mixing the ingredients and placing the bucket (with lid) a warm place, all you have to do is gently stirring once a day.
Some of the initial testings - oh, the possibilities, I'm so looking forward to play with this ...

A simple ami shawl and hat (modified with a crochet rim) made with homegrown
 japanese indigo.


  1. Wow, I love indigo! I've always loved the colour and the name of it too. When you say 'washing soda' do you mean sodium bicarbonate or some other thing?
    I love the sheep picture--it's like a before and after of white sheep wool, then some dyed indigo wool.

  2. It's Sodium carbonate, also known as Soda Ash. Yes, Indigo is a word from the land of myths and fables :)

  3. I have some frozen japanese indigo leaves and liquid left over from last summer.
    I did not get a good blue from them, but a turquoise greenish colour, and not wanting to throw away the dye, I froze it.
    Should I dare defrost and try again - any idea how what to expect?

    1. Hi Joanne, what method did you use? And did you freeze fresh leaves, or soaked?

    2. This comment has been removed by a blog administrator.

  4. I used the cold water method - so i wasn't expecting indigo blues - and I froze soaked chopped up leaves...what do you think? I also dared to dry and crush fresh leaves. I don't have a lot three or four tablespoons, but how should I treat them for dye?

    1. I tried the cold water method too, the colour turned out nice, but washed out after a couple of washes. I don't know if freezing will effect the dye potential, but you could try the method described here: http://riihivilla.blogspot.dk/2010/09/my-japanese-indigo-varitatar.html - or you could try this: http://www.indigrowingblue.com/Dyeing_With_Fresh_Indigo_Leaves.pdf
      Or perhaps a method using frozen leaves from Inda Flint could work for you. Jenny describes here, how she tried it with a handful of woad leaves: http://www.jennydean.co.uk/index.php/dyeing-with-frozen-woad-leaves/

      Considering the dried leaves, you haven't much to work with. Maybe you could try a gather some more this year, and extract the indigotin. Extracting requires a fair amount of leaves. Hope this can be of help to you.
      :) Mona

    2. Thank you Mona!
      I will check out the links, and am sprouting some new indigo seeds for a new crop this year. I will pay a little more care and attention with the process - last year I was in such a hurry to harvest the leaves, I left them too long standing in the hot sun and lost the best of the cold water extraction...
      Thanks again :)

  5. Ooooh... looks like fun.

  6. Hi Mona.
    I read your blog the fermentation of Indigo.
    And I am curious.
    Do I have to mix the recipe you showed into the plane water? I can't image only that materials is going on fermentation.