I did some research about different types of oils. Perhaps the three most common oils used in most of the soap recipes I found are olive oil, palm oil, and coconut oil. In fact, many recipes recommend 40% olive, 30% palm, and 30% coconut oils.
Olive oil contributes to a good conditioning bar, but it doesn’t produce a lot of lather on its own, and pure castille bars can be soft. I buy olive oil at the grocery store. Shop around and see which brands you like best and which grade. Some soapers prefer EVOO. I have not noticed a difference, and since light olive oil is cheaper, that’s what I use. Some soapers buy olive pomace oil. I have not tried it because it’s not readily available in the store, and I buy what I can find locally to save shipping charges. I have to order too much other stuff for soaping to worry with olive oil, too. Soaps with a high olive oil content take longer to saponify and need longer to cure.
Coconut oil contributes to a cleansing bar with a good lather, which is why some soapers make “bastille” (not pure castille, but mostly olive oil) bars with a percentage of coconut oil. I have a bastille recipe that is 75% olive oil, 25% coconut oil. It is recommended to keep use of coconut oil at 30% or less because more than that can be drying. Coconut oil can be hard to find in the grocery store in some areas. I buy the Louana brand at Walmart. Shop carefully. I saw the same brand of coconut oil I purchase for sale on Amazon via a third party seller. It was described as organic (it isn’t) and cost at least four times as much as the same size container in Walmart. Plus shipping.
Palm oil contributes to a hard bar. It’s a substitute for tallow when soapers want to create vegan or all vegetable oil soaps rather than using animal fats. Palm oil also contributes to a creamy, stable lather. It’s best to keep the amount of palm oil under 50% of your total oils because some people find it drying if you use more than that. Palm oil use can be controversial because of its association with rainforest depletion in the areas of the world where the oil palm is cultivated. You can buy palm oil from vendors that the Roundtable on Sustainable Palm Oil (RSPO) has certified meet criteria and procedures for manufacturing sustainable palm oil. Some soapers have stopped using palm oil altogether. It is an important issue to educate yourself about. I do use palm oil, but after learning more about the issue, I have decided not buy from a vendor unless it is RSPO certified sustainable palm oil. Bramble Berry sells sustainable palm oil. So do other companies, such as Soaper’s Choice.
Most of my recipes have these three oils. In addition, I like to use some of the following oils:
- Castor oil contributes to a nice, bubbly lather. It is recommended to keep the amount at 5% or less of your total oils.
- Shea butter adds moisturizing qualities and contributes to a harder bar.
I’m relatively new to soaping, so there are plenty of oils I have not experimented with. I have discovered some of these oils are located in odd places in the grocery store. On my last shopping trip, I managed to find sunflower oil by the Italian foods. Rice bran oil was near the olive oil, but it was on the top shelf, and my store only carried one brand. Safflower oil is also with the other oils. I have only used this oil once (my first recipe called for it), but it has a short shelf life and as David Fisher at Candle & Soap Making at About.com says, it has a “fairly unremarkable fatty acid makeup.” Sesame seed oil is stocked with the Asian foods and is said to be a good conditioner.
Many soapers swear by other products such as cocoa butter, mango butter, apricot kernel oil, palm kernel oil, avocado oil. I want to try some of these oils, but I haven’t had the opportunity yet. I have used grapeseed oil, but it has a short shelf life, and I didn’t notice anything missing in my soap when I haven’t used it. I plan to try using it as an oil for sugar scrubs. It is said to absorb quickly in the skin without leaving a greasy feeling.
The important thing is to experiment with the different oils using a soap calculator. My new favorite (and an old standby many soapers use and swear by) is SoapCalc. There are other good ones, too (see my Resources page). SoapCalc can give you a prediction about your soap based on the percentages of oils you use. You can easily change amounts without having to start over, too. I usually start with a base of olive, coconut, and palm oils, and add and subtract amounts from those base oils when I add other oils like castor oil and shea butter. The recipe I use most often uses 38% olive oil, 30% coconut oil, 17% palm oil, 10% shea butter, and 5% castor oil. I also frequently use Heidi Corley Barto’s basic recipe, which calls for 30% palm oil, 30% shea butter, 20% olive oil, and 20% coconut oil. I usually discount my lye by 5%, which leaves some unsaponified oil in the soap for conditioning purposes and also gives me wiggle room for slight measuring errors, preventing a lye-heavy batch of soap that would be unusable. SoapCalc and other lye calculators will help you figure out how to discount lye. By default, SoapCalc figures a 5% lye discount.
Some soapers swear by attending to INS values as a method for producing good soap. INS values were introduced by Dr. Robert S. McDaniel in Essentially Soap as a means for figuring out the iodine value and SAP value (saponification value). Supposedly, an INS value of 160 is the ideal, but many soapers make wonderful soap that isn’t close to that value. My recipe above has an INS value of 158, and Barto’s has an INS of 151. I can tell no appreciable difference between them in terms of quality, and they are both fairly easy to soap. I do notice my recipe has more lather, likely because of the castor oil, and hers produces a harder bar, likely because of the higher percentage of palm oil and shea butter. On the other hand, the first soap I made had a low INS value of about 121. SoapCalc’s scale recommends an INS between 136 and 165. Given that my soap with an INS value of 121 is really soft and just not all that nice to use, the recommendation seems sound to me.
Don’t be afraid to try out a few combinations using the lye calculator. It can be fun to experiment.
Another issue I ran into early on is not knowing how much essential oil or fragrance oil to use. Thankfully, Bramble Berry has a good Fragrance Oil Calculator that can help you figure out how much oil to use. Other vendors make recommendations. How much fragrance or essential oil you use will vary. Some fragrances and essential oils are stronger than others. If your vendor has a recommendation, it is probably a good idea to follow it because they have most likely tested it, and following their recommendation will save you time. However, if you don’t have a recommendation, try using about 5-9% percent of your oil weight. For example, if you have a 40-ounce oil recipe, you might try 2 to 4 ounces of essential oil or fragrance. Many soapers keep it simple by using 1 ounce per pound of soap.
An important note: some essential oils and fragrance oils can accelerate trace and cause your soap to seize, as I discovered when I used lilac fragrance oil. Floral fragrance seem to be especially bad about accelerating trace. When you use a new fragrance or essential oil, it is a good idea to take careful notes about what happens in case you need to make changes for next time. For instance, next time I use lilac fragrance, I will add it at a lighter trace, and I will not try to do anything fancy like swirling. I haven’t noticed a huge problem with most fragrances, and usually, your vendor will warn you if a fragrance can be problematic. I like that vendors like Bramble Berry warn you not to use certain fragrances in cold process soap at all.