Castor oil is an extremely unique fixed oil. It has a thick and viscous texture and a slight odor. In cold process soap, it contributes to large bubbles and is known for its cleansing properties. Due to its lathering ability, it’s a common ingredient in other soapy products such as solid bubble bath. It also adds shine and slip to lip products.
Castor oil is extracted from the seeds of the castor oil plant. The seeds are pressed to extract the oil within. It has a unique fatty acid profile, with 85-95% ricinoleaic acid, 2-6% oleic acid and 1-5% linoleic acid. In addition to bath and beauty products, castor oil is used in food and as a coating and lubricant in various industries.
Castor oil feels similar to glycerin with a thick and sticky texture. It also acts as a humectant on the skin, just like glycerin. The humectant properties make it a wonderful addition to leave on products, such as balms. Castor oil has a shelf life of about 1 year.
In cold process soap, castor oil is typically used around 2-5% of the total oil weight. I’ve found using more than 10% can lead to a slightly sticky bar. Even a small amount of castor oil (such as 1%) contributes to a stable and fluffy lather. Substituting castor oil for another oil in recipes is tricky; there is not another fixed oil that adds quite the same properties. If you don’t have any on hand, I recommend increasing the amount of coconut oil in your recipe to increase lather. Read more about substituting oil in cold process recipes here. Castor oil does slightly accelerate trace, so keep that in mind when adding it to your recipes. If you’re looking for a few cold process recipes with castor oil, check out the cold process soap tutorials below.
Left to right, clockwise: Pantone 2016 Spin Swirl Cold Process Soap, Emerald Swirl Cold Process Tutorial, Galaxy Clyde Slide Cold Process Tutorial
Castor oil created some interesting results in the Single Oil Cold Process Lather Tests. In this post, I made twelve soaps out of 100% of one oil. Below is the emulsified soap batter of 100% castor oil. Notice the thick, slightly sticky, gloopy texture. The castor oil soap hardened within the mold in just a few hours. I was a little surprised that the 100% castor oil soap produced lather. Click here to read more about the tests of each oil.
Castor oil has a thick and sticky texture, which led to very interesting results in the Single Oil Cold Process Lather Tests.
Castor oil is commonly used in solid bubble bath to contribute to fluffy bubbles. Check out the How to Make Solid Bubble Bath video below on Soap Queen TV to see the process in action. The recipe also contains liquid glycerin, baking soda and SLSA. The recipe is easy to customize with various scents and colors. In the LoveSpell Solid Bubble Bath DIY, the bars are colored purple and pink for a feminine look.
In lip products, castor oil adds shine and gloss. In the Radiant Red Lipstick video on Soap Queen TV, castor oil is used in equal parts with jojoba oil, along with various waxes for a rich, glossy texture. In the Rosy Red Lip Gloss, castor oil is used along with cera bellina wax for a soft, Vaseline-like texture. Adding castor oil to the Nourish Lip Balm Base adds a little more shine and gloss, as shown in the Beautiful Bronze Lip Tint Tutorial.
Left to right: Rosy Red Lip Gloss, Beautiful Bronze Lip Tint Tutorial
Castor oil has unique cleansing properties. Because of this, it’s a great addition to oil cleansers. In the Oat Oil Cleansers for Dry and Oily Skin, castor oil is used in both formulas. The idea behind oil cleansing is that it dissolves and washes away the sebum produced naturally by your skin, and replaces it with new “clean” oil. This leaves skin balanced, and does not cause skin to overproduce sebum. Click here to learn more about oil cleansing.
The Oat Oil Cleansers for Dry and Oily Skin both contain castor oil for its cleansing properties.
How to do incorporate the unique properties of castor oil into your products? I love using it in my cold process soap recipes when I want plenty of bubbles. =)
castor oil is a perfect ingredient in donkey milk soap!!!
Sounds like a great combination. 🙂
Hi. Soap Queen! My recipe is 55% Coconut Oil and 45% Olive Oil. But I wanted to add extra moisture to my soap. Can I add castor oil at trace for extra moisture or superfat? I used to add little shea butter at trace for extra moisture. I wanted to try castor oil. If yes, how much do you suggest per pound of oils? Hmmm…. 🤔🤔🤔🤔
Thanks and Have a Great Day! 😘
You can add castor oil if you like. At 2-5% it adds lather and moisture to your recipe. You may also try reducing the coconut oil and increasing the olive oil. If it’s used at more than 30%, it can feel drying on the skin. Learn more about that here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/sunday-night-spotlight-coconut-oil/
Remember to run your recipe through the Lye Calculator after any substitutions: https://www.brambleberry.com/Pages/Lye-Calculator.aspx
-Kelsey with Bramble Berry
Can I use something else than SLSA, as it is not very good for the skin. Our family has super dry skin, and I know this makes it even dryer.
In the Solid Bubble Bath, the SLSA is used to create bubbles. Without it, the recipe will just melt in the tub rather than bubbling. I would recommend bath bombs or fizzies instead! Most don’t contain SLSA. Instead, they use citric acid and baking soda, which causes a fizzing reaction in the tub. 🙂
Find lots of fun bath bomb recipes here: https://www.soapqueen.com/category/bath-and-body-tutorials/bath-fizzies/
-Kelsey with Bramble Berry
Can I use castor oil in melt and pour soap? I’m new to this and am not ready to take on the lye yet. Thank you
Hi Pamela!
We don’t recommend adding extra oil to the melt and pour bases. It can make them oily or dry. If you do, we recommend no more than 1 teaspoon of extra oil per pound of soap. That should provide the properties of the oil without affecting the soap texture too much. You may also like our Shaving Melt and Pour Base! It is nice and bubbly. 🙂
Shaving Melt and Pour Base: https://www.brambleberry.com/SFIC-Shaving-Melt-And-Pour-Base-P4384.aspx
-Kelsey with Bramble Berry
what is the difference between castor oil and castor soap?????
Hi Jade!
Castor soap is soap made with castor oil! Castor oil is often added to soap for cleansing and lathering properties. It creates nice bubbles in the bar. We usually like to add it around 2-5% in the recipe. 🙂
Read more about common soapmaking oils and how to use them here: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/free-beginners-guide-to-soapmaking-common-soapmaking-oils/
-Kelsey with Bramble Berry
If I’m making lipgloss to be put in a tube with a wand applicator, is castor oil a must have? I’m researching and for some reason have a negative connotation with castor oil- but it seems to achieve the consistency I want, castor oil is a staple in recipes? I planned to mix it with either hemp seed or vanilla infused grapeseed oil, mango butter, and cera bellina.
Castor oil would be amazing for gloss! It has a thick, shiny, sticky texture that works perfectly in lip recipes. It’s nice and stable. We used it in the Rosy Red Lip Gloss Recipe with great results: https://www.soapqueen.com/bath-and-body-tutorials/lip-products/rosy-red-lip-gloss/
Read more about making lip products here: https://www.soapqueen.com/bath-and-body-tutorials/lip-products/how-to-create-lip-product-recipes/
-Kelsey with Bramble Berry
I add between 2-4% castor oil in every soap recipe I make now, and have loved the qualities that it adds to the soap. I remember initially being scared of it, because my mother grew up in Scotland, and her mum used to make her drink it every night before bed, lol. Once I got over that image, I was able to use it and boy was I happy that I did. I use a pretty standard recipe usually, with olive, coconut, palm, tallow, and usually shea and almond with the castor oil. The result is a super moisturizing, bubbly, luxurious lather that cleans and makes the skin feel fantastic!
Castor oil feels so amazing in soap! I add it to all of my recipes too. Nothing better than big fluffy bubbles. 🙂
-Kelsey with Bramble Berry
I’ve only recently started adding castor oil to my tried and true recipe. It has a high coconut oil percent and I occasionally take a few ounces off the coconut oil and replace with castor oil and I sometimes use castor oil as my superfat to offset the high coconut content. Castor works especially well to superfat HP soap at the end of the cook because saponification is mostly complete then. I’ve had great results so far and plan to continue. It’s absurdly expensive at a local chain drug store, but a local grocery store has it at a very reasonable price.
I love adding a bit of castor oil to my recipes for bubbles! It works really well with coconut oil for some nice fluffy lather. 🙂
-Kelsey with Bramble Berry
I love using castor oil, I have about 5 recipes that I use for making cold process soap, and all but one have castor oil in them! I was making soap one night and realized I was out of castor. I could have changed the recipe, but then I would have to make new labels too! So I went to Walmart (yes, in my yoga pants and sloppy t-shirt I wear to make soap!), and paid a ridiculous amount of money to buy the last 2 four oz. bottles they had!
So 2 things that weren’t mentioned that I use castor in. I had made some true Castile soap, 100% olive oil, and even after it cured for a full year, it just doesn’t make hardly any lather. I have a couple of customers who want castile, but wanted some bubbles, so I made a batch with 10% castor and 90% olive. It made a huge difference, and even though I’m not a fan of castile, I did like the added castor. The other product I use castor oil in, is liquid soap! I have experimented with more recipes and tweaks than I can count, but I have found that I really like to have castor in every batch. It not only helps with the lather, but it just seems to make my hands feel more moisturized than liquid soap with no castor!
Now to throw in a request, I would LOVE it if you guys had Turkey Red Castor Oil!! I really like to stick with just a couple of suppliers, but it’s hard to find the oil in that form! That is all, thanks!! 🙂
Castor oil is so amazing, I love the lather it creates! It’s perfect for an olive oil recipe to add some bubbles. Also, thanks so much for your suggestion. I passed that along to our research and development department. 🙂
-Kelsey with Bramble Berry
I think the most reasonable price I have found in my neck of the Rocky Mountains of Colorado was indeed at Walmart….back in the pharmacy area, near the laxatives. It is Humco brand, very industrial looking label in a plastic brown transparent bottle; 6 oz for about $2.50. I have not found ANYONE that can beat that price.
We have castor oil you may like as well! It’s $3.36 per pound and because we go through it quickly, it’s always nice and fresh. 🙂
Castor oil: https://www.brambleberry.com/Castor-Oil-P3195.aspx
-Kelsey with Bramble Berry