Castile soap is one of the major components of homemade body care products. It used for cleansing the body, and is the component of organic shampoo responsible for cleaning your hair. The process of making soap at home really isn’t very difficult. You may find that you enjoy it so much that you turn it into a home-based business. You can also make soaps for bath and body gift baskets for your friends.
What is Castile Soap? Castile, or olive oil soap, uses an oil base, rather than animal fat. Though olive oil is the most common base, other vegetable oils, such as coconut, jojoba, almond, or hemp, can be used. The important thing to remember is that the soap is only considered organic if it is made from organic materials. If non-organic ingredients are used it is a natural, or herbal soap.
There are only 3 ingredients in a basic Castile Soap recipe; olive oil, lye, and water. Lye is caustic and reactive with both your skin, and certain cookware materials. You want to make sure you are using only stainless steel pots for this, not aluminum, and wear rubber gloves and goggles when handling the lye, and use heavy plastic or stainless utensils for stirring. You will also need a meat thermometer, a large bowl, and a some sort of mold to shape the soap. The most common types are long and rectangular and created a sort of loaf of soap that you can cut into bars.
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Oh, and a side note about the olive oil; it’s not necessary to get virgin, or extra virgin olive oil. These oils are prized for their taste and health benefits. You (hopefully) won’t be ingesting your soap, so %100 pure will work just fine, and is much cheaper.
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Put the olive oil into your stainless steel pot and heat over medium heat until the pot of oil reaches roughly 100 degrees. By the time this has occurred, your lye should have reached a workable temperature. Take your container of lye, and slowly pour it into your oil, using a spoon to blend it all together as you pour. Place the empty lye container back into the sink.
Now you want to stir steadily until you start seeing the soap come together, this is called trace, and it means that you can no longer separate the ingredients back into their original components. If you do this process by hand it can take up to an hour, 
but if you use a small stick blender, it can come together rather quickly. When everything is blended, and it has started to trace, go ahead add any fragrances or colors, and slowly blend them into the soap.
Once everything has blended together nicely, transfer your soap into your mold by slowly pouring it evenly in a back-and-forth motion along the length mold. Once you’ve poured everything in, go ahead and smooth out the top using the back of a butter
knife, or spatula.
The soap will continue to react, and it’s to store it someplace warm for the next 24 hours. If the ambient temperature of your house is fairly warm, you can simply place a towel over the top of your mold for insulation and let it sit out, preferably somewhere near a window that gets a lot of sun. Another option is to put your oven on its “warm” setting, and leave the mold in there with the door slightly ajar. Once the soap has sat for 24 hours, remove it from its mold, and slice into bars of soap. Allow these bars of soap to cure for at least 30 days before use.