Dual Lye Cold Process Soap with Henna

[eulani]

I've been playing with a recipe to add indigo henna to lye water to (hopefully) make a baby blue soap.
Last night I decided to try it with dual lye, 95% NaOH and 5% KoH since I want to use it in a CP castile recipe. I added the henna powder to distilled water and then added the lye and left it overnight in the fridge to test today as the henna requires time for the blue pigment to develop.
It hasn't turned to the desired colour, however interestingly enough, the mixture has thickened :???: It's a thin syrupy consistency. Interesting little experiment.

 

[Kittish]

I'm not sure if you mean just indigo, or a combination of henna and indigo, though it sounds like you mean just indigo. How much did you use? I had good results with about a teaspoon of indigo in a pound of soap.

What worked for me was to measure out a bit more distilled water than I needed for my soap, bring it to a boil then mix the indigo in. Let that sit overnight or longer, give it a stir, then measure out for my soap and mix the lye in. The soap came out a nice sky/light blue with darker specks evenly distributed. I've also got indigo infused oil, that I keep forgetting to use. The oil is a gorgeous purple that turns dark navy when I mix the indigo back up into it. It should make some pretty soap.

 

[eulani]

Thanks. It's "black henna" (indigo tinctoria), or just plain indigo For this experiment I used half a teaspoon in about 4oz (117g) of water, added 72g NaOh and 6g KoH to see if the lye extracted more dye. So, I will stick to mixing it with water and adding at light trace, works better for me. Was curious about the consistency change in the lye solution though. I might infuse some in avocado oil too.