Japanese Indigo Soap

Last October, I had the pleasure of meeting Maya of Infusions (you can read about it here). She gave me some precious gifts and soaping ingredients, and one of them was Japanese indigo powder.

Indigo 4

Japanese Indigo: raw powder and in soap

I love the colour of indigo and have always been curious to try it in soap, but had never been in possession of it until I met Maya. Now that things have quieted down after the holiday rush, I have the time to experiment with new formulae and ingredients.

Other than Maya’s post on soaping with Japanese indigo, I could not find much material on the subject. She had explained to me how to use it, but just to make sure I’m using it correctly, I emailed her. I don’t want to miss anything, so I thought I’d share her exact instructions:

As for the indigo, I have used it after making water infusion and as powder, added directly to the soap batter and also to the lye.

I used 1/2 teaspoonful of indigo powder for 12 ml hot water, infused for a couple of hours. I used about 2/3 (8 ml) of the infusion but what looked to me like a medium color may be considered dark by others. I think it is best to see the color of your batter and decide when to stop adding indigo-infused water as the color of the soap does not change much after the soap hardens. You can enhance the color by letting the soap gel.

The second method, adding dry powder directly to the soap gives you a speckled look. I do not remember how much I used but you can decide the amount of powder on the go.

Two things to keep in mind:
1. The color morphs to a very dark bluish gray if the powder is added directly to lye. It is best to add the indigo (in whatever form) at medium trace, after the saponification has advanced and the NaOH molecules have bonded with the oil molecules and cannot react with the indigo.
2. If you use EV olive oil, you will get a deep greenish blue due to the color of the olive oil.

Generally speaking, the indigo color is relatively stable in CP soap but it still fades a little with time. You need to keep it in a dark place to help the retention of color.

I decided to go with the first method, i.e. make a water infusion, and to add colour as needed after reaching trace. I ended up using all of my preparation, including the sediment that collected at the bottom of the glass. As you can see, the resulting colour is a bluish grey.  Indigo 1

I used olive oil, coconut oil, almond oil and cocoa butter with 2 milks:  yogurt and goat’s milk. For the essential oil blend, I used cypress, petitgrain, lemon 5-fold, orange 5-fold, cajeput, and basil.   It was only after mixing the EOs that I realised how yellow it was and that it would certainly have an effect on the colour. I thus used more of the EO in the uncoloured portion containing kaolin clay.  Predictably, it turned yellow.

It is not very obvious in the photos, but the indigo-coloured portion bleeds into the uncoloured part. The next time I make this, I will make it a solid colour. But because of the EOs, it will probably turn a greenish blue – which I don’t mind, because seriously, it smells fantastic!

Indigo 2

Indigo 3


Thank you, Maya, for letting me have this opportunity to soap with Japanese indigo. 🙂

Coming up next is another Japanese ingredient from Maya. Thank you for reading and have a wonderful week ahead! 🙂



30 thoughts on “Japanese Indigo Soap

  1. jjbaze

    Thank you for sharing, I like how the soap turned out, very pretty. Also the photography is really great, looks and shows off your soaps. 🙂

  2. Yvonne Bækgaard Pedersen

    Thank you for sharing Silvia. I have also been playing with Indigo and I must say I love to use natural colors, it just gives something extra to the soap knowing it’s all natural, don’t you think?
    Your soap turned out beautiful, you managed to make a delicate blue nuance. I got my Indigo online, do you know if there is any difference in japanees Indigo vs others?


    1. soapjam Post author

      I agree, Yvonne. There’s something special about an all-natural soap.
      This is my first time to use indigo. Maya had a post in her blog about Japanese indigo and another post on Indian indigo. They are supposed to yield different kinds of blue.

  3. Madame Propre

    Oh Sylvia, they are absolutely fabulous! You achieved a very tender colour, and a cloudy swirl!!! I am surprised it is still very blue, though you do have olive oil and EO. My indigo changes colour more easily than yours! Blues in general tend to turns green on me as soon as I add olive oil…. Congratulation, once again, I love your soap! and the haziness in the picture is a success!

    1. soapjam Post author

      Thank you, Madame Propre! Where is your indigo from? I don’t have the proper measurement for the amount of indigo I used. I just kept on adding! LOL!

  4. Vicki

    Lovely Silvia 😀 Is Japanese indigo very different to regular indigo do you know? It’s a really nice colour and I would be really interested to see what colour a solid bar is. And now I’m wondering what the next Japanese ingredient is going to be!

    1. soapjam Post author

      Thank you, Vicki! This is my first time to use indigo, but for more on both Japanese and Indian indigo, Maya wrote about it in her blog, infusionsblog.wordpress.com . I am intrigued by it and I’d like to experiment more. For my next post, it’s actually 2 Japanese ingredients in one soap. 🙂

  5. Infusions

    Silvia, your soaps look great – everything about them is perfect: the indigo color, the swirl (I have come to think of it as one of your signature designs) and the top of the soap and hope you will enjoy the other ingredient, too.
    I am glad you like the indigo and cannot wait to see your other soaps (indigo and others 🙂 ) I am sorry for the delayed reply to your email. There have been some new developments here but things are settling down and I am writing to you later today:-)

    1. soapjam Post author

      Ooh, I love the way your indigo soap turned out! You mentioned you used 1/2 tsp for that batch. May I know how much oil was used? Thank you, Gordana!

      1. Gordana

        I used less than half of teaspoon of indigo for 380 g of oils. I dissolved indigo in lye water. I would suggest you to strain this lye/ indigo solution in order to avoid indigo speckles in final product.

        1. soapjam Post author

          Thank you for the info, Gordana. Have you tried dissolving the indigo in water and adding it at trace? Maya said that for Japanese indigo, it is better to add the indigo as late as possible so that there is less reaction with the lye. I think this would make a good experiment. 🙂

          1. Gordana

            No, I did not try this method, but why not, I still have some quantity available 🙂 So, I will add this to my “to do” list, hope that I will make it soon! It will be interesting to compare our results 🙂

  6. Monica

    The indigo turned out beautifully Silvia! I really like the way you paired it with the yellow, they’re both a nice subtle tone which makes the soap appear very sophisticated.

    1. soapjam Post author

      Thank you, Monica! The indigo part continues to spread out into the uncoloured portion. I presume the whole thing will eventually turn bluish. 🙂

  7. Maja

    Isn’t it great to have soapy friends around the globe? !I received my indigo from Nat 2 years ago and I don’t know where it’d come from, but it behaved perfectly on me. I always add my colours after emulsification has taken place, but I don’t remember where I dissolved it into!? Maybe in some water, or oil. Anyway, it held pretty long without significant fading.
    Your soap looks lovely, as usual, I love how rich-swirled it is!

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