I have been leaving fermented rice water on my hair after shampooing and conditioning without rinsing it out. I can't find any websites that say you can do this, they say to rinse out after applying. I love the way my hair feels when it dries, but I'm not sure if I'm doing any harm to my hair like weakening it or maybe the fermented rice water could lighten my color treated hair. I just don't know what is in rice water. I hope it's okay because as I said, I love how it feels but there may be something in it that could do a lot of damage if I don't rinse it out. What say you? Thanks for any help you can give.
So, the short- and long-term effects of various substances on hair is a complicated area and one I'm not really equipped to advise on (and this site generally doesn't and shouldn't advise on health issues).
However, I did manage to find, among all the hip information-free websites, a break-down from a study on the effects of rice water on hair with the various components of unfermented rice water (other than water, obviously).
- 16% proteins
- 10% triglycerides (i.e. ordinary oils/fats)
- 10% other lipids (probably slightly less common oils/fats)
- 13% phytic acid (a chemical found in lots of everyday foods)
- 4% inositol (a sweet sugar alcohol and useful but not essential nutrient)
- 9% starch
- 17% other carbohydrates
- 21% other inorganic substances (esp. ash)
From: The effect of rinse water obtained from the washing of rice (YU-SU-RU) as a hair treatment by S. Inamasu, R.Ikuyama, Y. Fujisaki and K.-I. Sugimoto: Beauty Care Laboratory, Kracie Home Products, Ltd., 134, Goudo-cho, Hodogaya-ku, Yokohama 240-0005, Japan (Original in Japanese, translated abstract here.)
Fermentation will likely break down some of those carbohydrates into ethanol and methanol, but probably not all of them.