"Saponification is a process by which triglycerides are reacted with sodium or potassium hydroxide (lye) to produce glycerol and a fatty acid salt called "soap." The triglycerides are most often animal fats or vegetable oils. When sodium hydroxide is used, a hard soap is produced. Using potassium hydroxide results in a soft soap."
What is Saponification?
There is a heart of any process and the heart of making soap is Saponification. Without Saponification, there is no soap! This is the chemical reaction that turns oils and butters into beautiful artistic soaps!
When I started my journey into soap making, I did not fully understand this process. Why did I have to understand chemistry when I just wanted to make soap?? This knowledge is not necessarily needed but it does give you a better understanding of the process and helps you create the best product you can!
How does Saponification work and am I left with Lye?
Did you know the root word, 'sapo-' in saponification means soap in Latin? In fact, this name translates to the phrase, 'soap-making.' But with this chemical reaction, what happens to the Acid (oils) and the Base (Lye)? When the lye is added to water this is causes an exothermic reaction that causes the lye water to reach temperatures up to 200 ° F. This heat is a part of the Saponification process. As the chemical reaction between the oil and base occurs, the reaction changes the makeup of the Acid (Oil) and Base (Lye) creating a Salt (Soap). The lye has all interacted with the oils and been transformed into soap and glycerin. Both the lye and the oils have lost their original characteristics. In order to make sure you are using the right ratios to get the right reaction, you will need to use a Lye Calculator. These calculators will make sure that once the chemical reaction is complete, no lye is left behind in your finished product.
Another word you may hear when talking about Saponification is Superfatting. Many soap makers will add more oils and/or butters than are necessary for Saponification to ensure there is no lye in the final product, this is call Superfatting. We will often superfat soaps as it can add to a more luxurious lather to the soap and it can result in a soap that is more moisturizing. This does need to be done in moderation as the more "Free" oil you have in the soap, the earlier it can spoil as you have to consider the shelf life of the oils that have not undergone the chemical reaction.