What is Castile Soap?
Castile soap is a name used for soap made predominantly from olive oil.
Castile soap is also sometimes called Seafarer's soap because of its broad range of uses.
Castile soap originated in the Kingdom of Castile, where it was made from olive oil only. In Castile, barilla (an impure form of sodium carbonate obtained from plant ashes) was boiled with locally available olive oil, instead of tallow. By adding brine to the boiled liquor, the soap was made to float to the surface, where it could be skimmed off by the soap-boiler, leaving the excess lye and impurities to settle out. This produced what was probably the first white hard soap, which hardened further as it was aged, without losing its whiteness, forming jabón de Castilla, which eventually became the generic name.
The fine ashes used in soap-making were so valuable that they were one of the first products imported to England from its first colony, Virginia, in the early 17th century. The British Parliament later permitted free importation of some products used in linen manufacture in 1803 as it was so gentle and pure.
Our modern day castile soap is made in a similar way with our only ingredients being saponified (filtered through plant ashes to make water soluble) organic olive oil and water cold pressed to hold in the nutrients.