castile soap
Castile soap (pron. ka-ˈstēl) is a highly effective and versatile cleaner made from vegetable oils. It originated in the Castile region of Spain, where olive oil was combined with sodium carbonate to create a hard white soap that was sold throughout Europe as early as the 16th century. Since then, production has evolved to include other plant-based oils, such as coconut, palm kernel, hemp, and jojoba, which give soap makers greater control over properties such as lather, but the soap remains free from animal fats, making it ideal for vegans. castile soap