Castile soap, pronounced “kas-teel”, is rooted in the traditions of the Eastern Mediterranean where Aleppo soap makers made hard cleansing bars out of laurel oil and lye. Laurel oil is derived from the aromatic Laurus nobilis,an evergreen tree or large shrub with green, glossy leaves and is native to Syria.
To this day, the origins of Aleppo soap remain unclear. Claims that the Egyptian Queen Cleopatra and Queen Zenobia of Syria used Aleppo soap abound but have yet to be verified. As of this writing, we only know for sure that this important precursor to Castile soap cleansed the skin and hair of humankind for millenia.
The common belief is that the Crusaders brought Aleppo soap back to Europe with them during the 11th century. Since laurel oil was not available in this part of the world, it was replaced with olive oil in the Castile region of Spain.
Castile soap was born!
Castile soap is known today as any vegetable oil based soap. This distinguishes it from soaps made with animal fat such as tallow or goat's milk. Hence, the Castile soaps of today are commonly made with olive oil, coconut oil, hemp oil and others.