Vegetarians and vegans, rejoice: One of castile soap’s distinguishing traits is that it’s made purely of vegetable fat, rather than animal fat like tallow, or other animal by-products like goat’s milk (as is common for most other soaps). It was initially made with olive oil from Spain’s Castile region—hence, the name. Since then, castile soap has expanded to include a mix of vegetable oils like coconut, walnut, castor, hemp and avocado oil. In addition to being animal-friendly, it’s also an environmentally conscious choice, as the soap itself is completely biodegradable. Castile soap is unique in that it’s both gentle and strong; it’s gentle on skin because it’s made from saponified oils that have hydrating properties, but it’s an equally powerful cleanser that can tackle even the most stubborn grime.