A while back, on the SoapMaking Forum, one of the makers mentioned that she adds rice to her soap and it's one of her favourite soaps. After some discussion, I decided to try it... and immediately fell in love with it.
I decided to use Jasmine rice, just because I happened to have some Jasmine fragrance oil and a large bag of Jasmine rice. First, I washed the rice thoroughly and used that wash water to dissolve the lye. Because of the starches from the rice, the lye liquid quickly turned into a mush, thickening up almost like a pudding. I've never seen that before.
Once the rice was rinsed, I cooked it in more than double the amount of water usually used for cooking rice and I overcooked it, almost to the point of mushiness. I drained the water, reserving all of it; the rice was blitzed in a Magic Bullet, along with enough of the cooking water to create a fairly loose slurry.
When I was ready to put it all together, the slurry, along with some rice flour (that's the thrice part) was added to my oils. The lye rice water was added and, once the batter reached trace, I added the Jasmine fragrance oil.
So, what does rice bring to the soap? Rice has been used for centuries in Asian skin care. According to articles I've read, the geisha used to wash their faces in rice water; they were known for their flawless skin. According to an article in the Daily Times of India, rice "revitalizes and protects the skin from sun damage. It comes loaded with antioxidants that fight free radicals and give you a more youthful-looking skin. It helps in skin brightening too. It's considered a mild exfoliator, making it ideal for daily use."
Granted, the article is talking about a rice puree used as a masque and washing with rice water. Truth be told, soap doesn't really stay on your skin long enough to provide any real benefits, other than cleansing.
In this soap, the rice provides an amazingly silky, creamy lather. I was pleasantly surprised the first time I washed with it. I have dry skin and I found that it didn't strip my skin, leaving that dry, tight feeling. I still used a moisturizer because, as I said, I do have dry skin. The light scent of the Jasmine fragrance oil made this soap feel like an indulgence. I can see why rice soap is as popular as it is.