Organic 201: Castile Liquid Soap

Castile liquid soap is the original truly natural, multipurpose foaming liquid for nearly every cleaning and hygiene need. Read: Different dilutions and formulations for different solutions. Unlike detergent chemical bundles like sodium lauryl sulfate and company, castile liquid soap is made from olive and coconut oils, lye (potassium hydroxide) and water. Other oils such as shea butter, argan oil, avocado oil etc. can also be cooked in as small percentages to modify the product.
Castile soap can be adjusted to make pump foamer liquids, cleaning sprays of various strengths, and pump soaps. Use full strength in pet shampoos, laundry, dish, floor, exterior surface and other cleaning concentrates, hand and foot and oily skin or camping soaps. Sprays can be diluted for glass, car interiors, household, and commercial surface cleaning and even oven cleaner.

Vegetable oil liquid soaps can also be thickened into gel soaps with a wide range of viscosities. VT Soap can make you anything from a thick liquid/thin gel to a barely pumpable solid. Our unique gelling process adds only organic guar gum and glycerin to the soap base. We utilize Standard Base, which we market as castile soap in hand and foot gels, and we add extra olive, shea butter or other exotic oils with extra aloe to create softer body gels.

The predecessor to modern castile liquid soap appears to have emerged in the La Castilla region of Central Spain in the early 1700’s. Hence the name Castile Soap. It is also quite possible that the art of soapmaking was brought to Spain by the Arabs who conquered and held the region for 700 years. This is not far fetched given the rich and ancient tradition soapmaking has historically in Syria and other areas of the Levant. Or it could have migrated and then evolved from Marseille in Southern France, which has a rich history of soap making dating at least to the mid 1300’s and likely, well before.

Legend has it a type of liquid soap was made by boiling small batches of olive oil, water and ash lye (potassium carbonate) to a smooth consistency in Central Spain by at least the early 1700’s. I would venture to say it came with the invasion of the Moors a thousand years earlier. If you love soap thank the Arabs. Local soap makers began adding coconut oil after a particularly poor olive harvest created an olive oil shortage. They liked the results and their customers clearly preferred the coconut and olive blends over the pure olive oil ones. This makes sense when you remember that during this time in European history soap was mostly used for laundry, and bathing was considered a seasonal chore. Pure olive oil soaps would likely be sticky and difficult to rinse out of cloth; especially in cold water.

Vermont Soap developed its own unique slow cook process to produce a variety of natural liquid soap bases that we certify to USDA organic food standards. USDA organic certification is a program that audits for naturalness and safety while promoting healthy fertile soils that store carbon and feed future generations.
Your soap bases are manufactured to ISO Good Manufacturing Processes and certified by Underwriter Laboratories. Our USDA auditor is Vermont Organic Farmers a division of NOFA-VT. Vermont Soap puts nearly 175 products a year through organic certification for ourselves and our clients.

To learn more call us at 802-388-4302 and tell us about your product. Or email us

Did you know…? Vermont Soap was the first company anywhere to bring a natural gel soap to market. It took 76 tries until we were successful, but we did it. Gel soap was almost marketed as Formula 76.  Aren’t you glad we didn’t?


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