While some herbs are found only in Asia, others have equivalents in the western world. Searching for the Latin names of the herbs which are used in both Chinese and Japanese traditional medicines can be quite an experience though. After one such an experience, I found out that the herb called “shikon” (purple root) in Japan is called Lithospermum erythrorhizon and is a relative of the alkanet (Alkanna tinktoria) which I believe is used in Europe. It belongs to the same Boraginaceae family. Though the genus it belongs to is different from that of the alkanet, the roots of the plant are used to extract a natural purple dye. Despite its long history as a medicinal plant in both China and Japan (and probably in other parts of Asia) research has been done only recently to reveal some of the benefits for the skin.
About two years ago, there was a shikon boom in Japan and many soapers, including me :), began using it. As with every other colorant, be it natural or manmade, the density of the color depends on the amount of the substance used. I usually use about 30 g of chopped root in 200 g sunflower oil and use all the oil for a 500 g batch to get a dense purple color. However, this time I used about 1/3 of the above amount and got the pale purple color below. (To compare, you can see the pictures of one of my other shikon soaps at https://infusionsblog.wordpress.com/2012/09/24/here-comes-the-next-autumn-soap/)
I have noticed that when I use herbs in my soaps (even if only for coloring them) the lather gets finer and lasts longer. Since I am no chemists, I have no explanation why it is so. I will be very grateful if somebody can help me with this “why.”
I wish you a sunny day!