What is and what isn’t Castile soap is always up for debate it seems. A lot of soap makers maintain that Castile soap is 100% olive oil, water, and lye and to replace some of the olive oil with other vegetable oils would make it Bastille soap. Which is still primarily olive oil in content but includes other vegetable based oils.
You can walk into many stores and find Bastille soap sold as Castile soap and the argument continues among them.
Let’s look at the history of olive oil soap.
What we now call Castile soap was first believed to have been made in the same region in Syria as Aleppo Soap, in which incorporates laurel berry oil with olive oil. “Castile” is named after a region in Spain, which it was given after the Crusades( 1095-1291) brought* it to Europe and the Europeans named it as such. However, the process of making 100% olive oil soap was spread all around the Mediterranean region.
The true origins of soap are lost to time and we are left with legends, the word soap itself is believed to be named after Mount Sapo, a fictional mountain somewhere in the vicinity of Rome. The earliest known documentation of soap making was written down by the Greek-Egyptian alchemist Zosimos of Panopolis around 300 B.C.E. The oldest soap ever found was excavated in the ancient city of Babylon and dated back to around 2800 B.C.E.
There are several other variations on 100% olive oil soap that I have found throughout history, Savon de Marseille was an olive oil soap made in France with sea water first documented in the 1300’s. Nabulsi soap which was traditionally made by women in West Bank, Palestine before there was an industry, before the 10th century. Beldi soap also known as Savon Noir which has been made in Morocco for centuries is a gel like soap made from macerated olives, ashes and olive oil.
Regardless of what you call it and why, 100% olive oil soap is a very mild and wonderful soap, it takes about a year for it to fully cure. Depending on the type of olive oil you choose to use this soap may take hours or days to become solid enough to unmold. Once it hardens it can become crumbly so you have to keep an eye on it. Mine did become crumbly and work prevented me from cutting sooner but I was able to hide most of the crumbling when I trimmed up the edges. I recommend checking it daily so you do not end up cutting a soap that will crumble on you. I do highly recommend saving good quality olive oil’s for your kitchen and using lesser quality olive oil or pomace for your soaping needs.
This soap will need about seven months to a year for curing, some people even wait longer, you will want to select a fragrance that will really last, if you choose one at all. A large portion of fragrances will loose their scent before the cure would be finished. A steep water discount gets you the lower end of the cure time, I did mine at 33% of the oil weight or roughly a 28% lye concentration. Before this soap is fully cured it can feel sticky when used. it’s not a soap to make if you are an impatient soaper.