If Castile soap were a high school student, it would be voted “Most Likely to Test a Soap Maker’s Patience.” Castile soap, named for the Castile region in Spain where it originated, was originally defined as soap made with 100% olive oil. Today, you’ll find Castile soap made with other oils, like coconut and palm. As a soap maker, I can understand why this shift took place.
Soap made with olive oil as 100% of the oil in a recipe can be a challenge to work with. After adding lye water to the oils, it can take a very long time for the oil and lye to react and start to turn into soap. This means a soap maker has to spend more time mixing the batter to ensure the full chemical reaction, known as saponification, takes place.
Because olive oil is a liquid oil, there is a lot of moisture that needs to evaporate from the bar. After pouring the soap into the mold, it can take several days before it hardens enough to be removed and it can take up to a year of curing for a bar to reach its full potential. The normal four to six week cure time recommended for most handmade soaps doesn’t work for 100% olive oil soap. A short cure time results in a softer bar of soap that doesn’t lather very well and isn’t as gentle on the skin as it could be.
So, why do I use olive oil in almost all of my recipes? Olive oil is highly moisturizing and it makes skin feel great. Additionally, like rice bran oil, its slow reaction time makes it an excellent oil to use when I want to achieve beautiful swirls and designs in my soap.
I don’t have the patience to wait a year for my soap to cure so I do some things to help it along. I add coconut oil, which helps boost the lather, and palm oil, which helps the bar to harden faster. I’ve experimented with using olive oil at up to 80% of the total oils in a recipe and love the results. The lather is thick and creamy instead of bubbly and my skin feels soft and lovely after using it.
If you are interested in giving olive oil soap a try, you’re in luck! The Emmet Street Creations Etsy store has one pound bags of unscented 80% olive oil soap on sale for $10. The lack of fragrance makes this soap an awesome choice if you normally have sensitive skin. The low price makes it easy to stock up and save!
Do you have a question about the soap making process? Ask it in the comments or on our Facebook page and I’ll do my best to answer it in a future post.