Tag Archives: Japanese Indigo Soap

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! 🙂