Why Lye?
Lye can sound like a frightening addition to an otherwise lovely list of natural ingredients found in handmade soap. We've seen the labels with the bright red "DANGER" warnings. Why are we adding something that seems so harsh and scary to something meant to be gentle and beneficial for our skin?
Simply put, you can't make soap without it!
Lye (sometimes referred to as sodium hydroxide or caustic soda) is a necessary ingredient in soapmaking. However, when made correctly, lye does not remain in the end product. That bar of handmade natural soap you picked up from the farmer's market isn't going to give you a nasty chemical burn the instant you use it. That's because the soapmaking process involves combining lye with oils and/or fats, which causes a chemical reaction that changes both the lye and the oils on a molecular level, forming soap. This process is called "saponification." The lye is completely used up during saponification, leaving you with gentle and lovely natural soap.
Most soap is made using this method. When checking the labels of your favorite soaps, you may find words like "sodium cocoate", "sodium palmate", or "sodium tallowate". This simply describes ingredients like coconut oil, palm oil, or tallow that have reacted with sodium hydroxide. In liquid soap, potassium hydroxide is used instead of sodium hydroxide, so the ingredients may be listed as "potassium cocoate", etc. You may also see ingredients listed as saponified olive oil or saponified lard. Again, this is describing the olive oil or lard as having gone through the saponification process (reacting with lye) in order to become soap.
If you don't see anything like this in you soap's ingredients, watch out! Look for ingredients like sulfates (sodium lauryl sulfate and sodium laureth sulfate in particular), which are lather-producing chemicals that strip oils and will over-dry skin and hair. These are commonly used in soaps that are actually classified as "detergents" - yuck! In our humble opinion, it's best to avoid these kinds of "soap" and stick with the good stuff - handmade and natural and glorious!