Hi there!...I have been trying to perfect a shampoo bar for some time now and I finally nailed it. I have thick(ish) dark curly hair which I color every month. Every shampoo bar recipe I tried and every commercial poo bar I bought ended in disaster.
There are 3 factors for a perfect shampoo bar.
First key point is not to superfat the shampoo bar. Our skin is different than our hair. Soap bars are superfatted minimum at 5% so that they condition and moistorize the skin. This is too oily for the hair. Thats why some people say their hair is still oily after wash.
Second key is the lather. you need to use oils that have high lathering and cleaning properties like babasu oil, coconut oil. Also the lather should be persistant so that you should be able to work the lather without needing more soap. This is provided by cocoa butter.
Third key is the softness and the quality of water. If you have hard water, no matter how good your shampoo bar is, you will end up with residue and stiffness. It is a good idea to invest in one of those shower head filters. I bought one recently and it is great! they really work.
Here is the recipe I used.
50% coconut oil
25% cocoa butter
25% avocado oil
superfatted at 3%
I also used 33% water discount method. if you use this method, be careful, the soap gets very hard after the trace so be quick to mold it after trace.
I used coconut milk powder and silk as additive, nettle, rosemary, peppermint essential oils and benzoin tincture as fixative. You need to cure this soap for at least 3 weeks or more.
I know this does not sound like a perfectly balance soap. But this is not a soap, this is a shampoo bar!
My hair is perfectly clean and silky soft now. Also smells lovely. I still use conditioner but I am reducing it at every wash. I will stop using it completely but I am doing this gradually. This recipe and soft water worked very well for my hair. Good luck with your experiments!