If you are new at soap making, castile soap is the perfect start for you. It’s an easy recipe, doesn’t require a lot of ingredients and there are plenty of ways to use it.
But first, a bit of history…Castile soap is known to have originated from the Castile region in Spain around 1567. It’s one of the oldest soaps and is made from 100% olive oil. It’s known for being a mild and soothing kind of soap, suitable for sensitive skin. Many castile soap recipes include other oils as well to balance the soap. Each oil contributes different properties to the soap, but olive oil always remains the main ingredient.
Another thing you should know about Castile soap is that it requires 6-9 months to cure. You could even leave it for a year to cure. You may have heard or read that 100% olive oil castile soap is very soft and has a slimy lather. Initially it is very soft, that’s why it will take more than 2 days before you will be able to unmold it. Then, if you leave the soap to cure for the proper period of time, you will enjoy a mild, hard, long-lasting bar of soap, with a nicer lather than when it’s left to cure for a few weeks.
Which olive oil is suitable for soap making?
When we were looking for castile soap recipes, we noticed that none of them specified what grade of olive oil we should use. As it turns out, all the grades of olive oil have almost the same fatty acids, so it doesn’t make a big difference which one you are going to use to make soap. Their main difference lies in the extraction process – the first oil that comes from the very first extraction is the “virgin” olive oil – and has an impact on flavor, color, vitamins and other nutrients. However, keep in mind:
- The higher the grade the more expensive the oil. The higher grade oils can be used for cooking, whereas pomace oil cannot.
- Virgin or grade A oils are lighter in color and make lighter soap. The pomace oil is more greenish, but the green color can come through in the final soap.
- Pomace olive oil can speed up the time it takes for the soap to get to trace.
- Most soap makers use refined, grade A or pure olive oil.
- Olive oil makes great, mild, moisturizing soap, so you’ll probably want to use it in other soap recipes as well.
Below you’ll find the traditional – 100% olive oil – recipe, as well as 2 variations of it.
Castile soap recipe (100% olive oil)
1000 gr olive oil
129 gr sodium hydroxide (lye)
300 gr distilled water
This recipe has a 5% superfat level. Check step 3 on the cold process post to learn more about the superfat technique. For the 100% olive oil recipe we use less water. Normally we would use three times the quantity of the lye, which gives us 129×3=387 grams of water. Instead, we use only 300gr. This technique is called “water discount” and it will help make our soap harder and cure faster. Because 100% olive oil soap takes a long time to harden and cure, water discount is highly recommended. Bear in mind that the water discount technique results in a more caustic lye solution, so make sure to wear your safety equipment.
Variation #1 (80% olive oil, 10% palm oil, 10% coconut oil)
800 gr olive oil
100 gr coconut oil
100 gr palm oil
134 gr sodium hydroxide (lye)
400 gr distilled water
This recipe has a 5% superfat level. The palm oil gives the soap hardness and more stable lather, whereas the coconut oil gives a more bubbly lather. The first variation includes a small percentage of other oils, so that it retains most of the properties of the Castile soap.
Variation #2 (60% olive oil, 20% palm oil, 20% coconut oil)
600 gr olive oil
200 gr coconut oil
200 gr palm oil
139 gr sodium hydroxide (lye)
417 gr distilled water
In the second variation we added a bit more palm and coconut oil, which will increase their properties into the soap.
Note that in the first and second variation we didn’t use the water discount technique, because no1: we use less olive, which means less time to cure, and no2: palm oil will make the soap harder.
Use the cold process method as shown in this post, plus the following specific steps:
- Mix the lye with the oils when both temperatures reach 43oC (110ºF)
- Keep in mind that it will take more than 2 days to unmold the soap, perhaps even a week.
- If you make the 100% olive oil recipe give it 6-9 months to cure and if you make one of the two variations give it at least 4-6 months to cure. The longer you’ll leave it to cure, the better (that goes for all soaps). We know it’s a long time, but at the end you’ll have a high quality, gentle, yet cleansing product.
If you have any questions or suggestions, please leave a comment below & we’ll be happy to help you! Good luck!