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View Full Version : Shampoo Bars without lye??



Sunny Elf
March 22nd, 2012, 04:09 PM
I've been looking into making my own shampoo bars, but the thought of lye in something used for my hair scares me! I mean, lye is something that you don't want your skin to be near. So that confuses me! When it's mixed with the oils, does its chemical structure change so that it isn't actually lye anymore?? What happens there? It just seems lye+hair would equal hair frying up and falling out and burning your scalp off, or something like that...shudder: Can someone explain the chemistry of how that all works?

And, is there a way to make a shampoo bar without lye? If so, what would you use as a substitute?

Roscata
March 22nd, 2012, 05:47 PM
Someone explained it here: http://forums.longhaircommunity.com/showthread.php?t=90052&page=16

This is the quote:

Soap is made with lye, however the lye reacts with the oils so that no more lye remains in the finished product. Lye and oil react in a process called saponification. While there was lye in the starting materials, there is no more lye in the end product. Soap bars are made with excess oils, so that there is more than enough to make sure all the lye reacts.

You shouldn't be afraid of using soap bars because of the lye, because once it reacts, it no longer exists, it is not there.

Take for example regular table salt, which is made of sodium and chlorine. Sodium on its own is very reactive metal, in fact it reacts very violently with regular water! Chlorine on its own is a very toxic gas!
But when you put them together, the product is very useful, and in fact essential to life.

So would you avoid table salt because its made of two very toxic things?

(Im a chemist btw)

ETA: in the end I just want to assure you that most soaps made my soapmakers such as CV are very natural, and totally safe!


ETA: I hope that helps. :)

Mairéad
March 22nd, 2012, 07:04 PM
Lye is what makes oil and fat into soap. There is no more lye left over if soap is made properly.

Sillage
March 22nd, 2012, 07:14 PM
And, is there a way to make a shampoo bar without lye? If so, what would you use as a substitute?

There are syndet shampoo bars which are made from synthetic detergents (like SLS) and contain no soap and have not been made with lye. But like Mairéad said, when you make soap correctly there is no lye left over.

Anje
March 22nd, 2012, 07:30 PM
The very simple explanation is that lye + fat = soap + glycerin. Soap is a lot like those membrane lipids you probably heard tons about in biology class; it has a charged polar end and a non-polar end (is amphipathic). Essentially, the lye binds to the fatty acid to make the charged end. The whole reaction is called saponification.

When soap and shampoo bars are made, the crafters normally add a small excess of fat, to ensure that not only is all the lye reacted, but that there's some extra oil present in the finished product to make it more moisturizing.