January 28, 2012: All of the SUDSon

Soooo.....aaap. When I set out to learn how to make soap, I did not know the adventure I was in for! Let's just say that it is certainly put both my creative and science skills to the test.
As a biology teacher, I spend a good amount of my day (and year) discussing the chemistry of living things. Hmmm... sounds so interesting huh? Well I really do think it is fascinating. Even better now that I can apply it to making natural soap in my kitchen!

Ever notice that cleaning a greasy pan with just plain old water does not work to well? The problem is that water is polar (the molecules act like little magnets - with opposite charges at each end) which causes it to be attracted other things polar but repel things like oils and greases which are non-polar. This is why water and oil "don't mix." If you add some soap though... viola! You can clean your pan (or your greasy hair or body - gross)! Soap acts like a mediator, causing oil and water to "shake hands" and get along - mix. Why can soap do this, you ask? Soap has a polar end (which connects to the water) and a non-polar end (which connects to the grease) creating a link between the two. The process of making soap is fantastic! The website that I used (mostly) to learn is How2Soap. The video below explains the basic ingredients:


So, the ingredient, Lye, is 100% NaOH (sodium hydroxide), which is a very strong base and can cause severe burns. When a base, such as NaOH, combines with an acid, such as HCL (hydrochloric acid) it undergoes a neutralization reaction. (NaOH + HCl --> H2O + NaCl.... OR sodium hydroxide and hydrogen chloride will make water and salt! - aka.. not harmful!)

So, the oils that are used in soap-making, contain molecules called "fatty acids" which are non-polar, and, obviously, acids! So the reaction between the lye and the oils is a neutralization reaction that creates soap and water. During the "curing" process, the water evaporates. The remaining soap molecules contain the fatty acid end (non-polar end that will like the grease!) and the polar end (that likes the water!). The entire process of making soap this way is called "cold process." Viola!

The video below explains the basic chemistry of soap:


So my next step (next day)... is to make soap! Stay tuned!