Castile soap is soap traditionally made entirely from olive oil. It originates from the Castile region of Spain, which is where it gets its name. To choose the best Castile soap, carefully check the ingredients, and look for some that is made with extra virgin olive oil, which is considered the best for making this soap and is believed to produce a purer, more authentic product. This soap is known to be free from artificial additives and to be kind and gentle on the skin.
The best Castile soap is pure and rustic-looking, in tones of greenish brown. Although extra virgin olive oil is best, other oils are sometimes used that are cheaper and more easily obtainable, such as Pomace olive oil or vegetable oil. Some Castile soaps are produced using coconut oil, which is drying to the skin and can cause allergies in some people. Many producers use no olive oil at all, and these products are not considered authentic.
Animal fats are sometimes used, partly enhance cleaning ability. This is considered acceptable. The acidity levels in animal fats closely matches the acidity levels in human skin, ensuring that it does not irritate or have a drying effect.
This soap should, as a general rule, contain only ingredients that are fit to eat. If the ingredients are not fit for consumption, some believe that it is unfit to put on the skin. Castile soap of excellent quality should not be overheated during the production process because byproducts are created as the olive oil breaks down. The nourishing properties within the olive oil are retained if it is not overheated. Leaving the liquid soap to set at room temperature is sufficient.
Good Castile soap does not lather, and this is a sign that it is made solely from olive oil. The soap should feel exceptionally mild and gentle on the skin and not have a drying effect. Castile soap should be free of additives, so if a scent is detected, then the soap might not be of an excellent quality because of the addition of perfume. Additives such as potassium hydroxide also are sometimes used. This chemical is an organic compound with a corrosive nature and would not be found in a natural product.
The cleaning abilities of Castile soap are superior to many soaps. This soap also should last a long time and is easily used in a solid bar shape. The liquid version is commercially available, but this is not its traditional form and might contain additional ingredients.