If you use natural body care products, you probably have heard of Bronner’s Castile Liquid Soap. People call it the “Swiss-army knife” of soap. It’s an all natural liquid Castile soap that has a ton of uses. Use it as a body wash? Yep. Liquid Castile soap is gentle enough for people with the most sensitive skin. Use it as a shampoo? Yep, even on babies’ hair. Use it as a dishwashing detergent? Yep. Use it as a laundry detergent? Yep.
Dr. Bronner’s Pure-Castile Liquid Soap is great. Except one thing! It contains palm kernel oil. Palm oil production has led to “deforestation, habitat degradation, climate change, animal cruelty and indigenous rights abuses.” I explained in detail why I don’t use palm oil, including the so-called fair trade or sustainable palm oil in this post. No Dr. Bronner’s Castile Liquid Soap for me. Instead, I make my own DIY liquid Castile soap. It can do all that Dr. Bronner’s liquid Castile soap can do. Want to know how I make it? Read on!
What is Liquid Castile Soap?
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Liquid Castile soap is a liquid soap that’s made with olive oil. Olive oil soap has been made and used for millennia. It’s popular because it’s gentle on our skin. It can be used by people with the most sensitive skin, like babies and children. The first olive soap is the Aleppo soap, made in Aleppo, Syria. Yes, the same Aleppo that has been on the news, but for very unfortunate reasons. During the 11th and 12th centuries, the Castile region of Spain began to make its own olive oil soap. That’s why we now call olive oil soap “Castile soap.”
Castile soap often isn’t made with only olive oil. For example, Dr. Bronner’s Fair Trade & Organic Castile Liquid Soap is made with 5 different kinds of vegetable oils: (1) coconut oil, (2) palm kernel oil, (3) olive oil, (4) hemp oil, and (5) jojoba oil. The order of the ingredients tells me that this Dr. Bronner’s liquid Castile soap has more coconut oil, and palm kernel oil, than olive oil. My educated guess is that Dr. Bronner’s Fair Trade & Organic Castile Liquid Soap is made with approximately: (1) 35% coconut oil, (2) 30% palm kernel oil, (3) 25% olive oil, (4) 5% hemp oil, and (5) 5% jojoba oil. Let me know if you want to know how I come up with these educated estimates. I can give you a detailed (and a total nerdy) explanation on these percentages. 🙂
DIY Liquid Castile Soap
Prep Time: a day or 2. Making DIY liquid Castile soap involves cooking the soap for about 5 hours, and then waiting another 10 to 12 hours for the soap paste to dilute and turn into liquid Castile soap.
Yields: about 55 oz of DIY liquid Castile soap
Ingredients for DIY Liquid Castile Soap
- Coconut Oil – 10 oz. I use Trader Joe’s Organic Virgin Coconut Oil. You can also use other brands of pure coconut oil, like Carrington Farms Organic Extra Virgin Coconut Oil, or Viva Labs Organic Extra Virgin Coconut Oil.
- Olive Oil – 4 oz. I use Trader Joe’s Imported Olive Oil. You can also try other brands of pure olive oil, like La Tourangelle Extra Virgin Olive Oil, or Kirkland Organic Extra Virgin Olive Oil.
- Hemp Oil – 1 oz. I use Nutiva Organic Hemp Oil. Other brands of hemp oil works too, like Canada Hemp Foods Organic Hemp Oil, or Dr. Adorable Organic Hemp Seed Oil.
- Jojoba Oil – 1 oz. I use Now Foods Organic Jojoba Oil. You can also try Leven Rose Organic Jojoba Oil, or Radha Beauty Organic Jojoba Oil.
- Potassium Hydroxide (KOH, aka lye) – 4.1 oz. I use Mollys Products Potassium Hydroxide Flakes. Make sure you use potassium hydroxide, not sodium hydroxide. You use sodium hydroxide to make hard soap bars.
- Distilled Water – 6 oz to make lye solution. An additional 34 oz to dilute DIY liquid Castile soap paste. You can find distilled water in your local supermarket.
- Vitamin E – 25 drops. I use Now Foods E-Oil. You can also use Sundown Vitamin E Oil, or Trader Joe’s Vitamin Oil E.
- Glass Container – a 1/2 gallon glass container.
Ingredients Compared
To make DIY liquid Castile soap, I use all the ingredients found in Dr. Bronner’s Castile Liquid Soap, except palm kernel oil and citric aid.
| Dr. Bronner’s Castile Liquid Soap | DIY Liquid Castile Soap |
|---|---|
| Water | Water |
| Coconut Oil | Coconut Oil |
| Potassium Hydroxide | Potassium Hydroxide (KOH, Lye) |
| Palm Kernel Oil | |
| Olive Oil | Olive Oil |
| Hemp Oil | Hemp Oil |
| Jojoba Oil | Jojoba Oil |
| Citric Acid | |
| Tocopherol | Tocopherol (Vitamin E) |
How to Make DIY Liquid Castile Soap
Be sure to take all necessary precautions when working with lye. You can read more about suggested protective gear in this post. It’s never a good idea to work with lye when children or pets are around.
(1) Make lye solution. In a well-ventilated place, add 4.1 oz of Potassium Hydroxide (KOH) to 6 oz of distilled water. Never add water to lye.
Use a silicone spatula to carefully mix your lye solution. Set the lye solution aside. When it’s ready for use, it will turn from cloudy to clear. It took about 10 minutes for me.
(2) Add coconut oil, olive oil, hemp oil and jojoba oil in a crock pot. Turn the crock pot to high heat to melt and mix the oil.
(3) Once all the oil is melted and mixed, carefully pour lye solution into the crock pot.
(4) Mix oil and lye solution using a silicone spatula for a few minutes. Then use a stick blender to bring the mixture to light trace (vanilla pudding consistency). It will take a little time, at least 15 to 20 minutes.
(5) Cover your crock pot. Cook your DIY liquid Castile Soap at high heat. For the first hour of cooking, check every 15 minutes to see if your soap has separated (it happened to me!), or has escaped outside of the crock pot.
(6) If your DIY liquid Castile soap separated. Use the stick blender to mix it again, and bring it back to trace. It took me about 5 minutes.
If your DIY liquid Castile soap tried to escape the crock pot, use a silicone spatula to stir the soap mixture. That should deflate it.
(7) Cover your crock pot again. Cook your DIY liquid Castile soap on high heat for 5 hours.
Here is my DIY liquid Castile soap after 4 hours of cooking.
Here is my DIY liquid Castile soap after 5 hours of cooking.
(8) Do a hot water test. Add 1/2 oz of the DIY liquid Castile soap to 1 oz of hot water. If the soap melts and the soapy liquid isn’t super cloudy (see picture below), the soap is ready to be diluted. If the soapy liquid is very cloudy and milky, then cook the DIY liquid Castile soap for another 30 minutes. And repeat the hot water test.
(9) Add 34 oz of VERY HOT distilled water into the crock pot. Make sure it’s very hot water. Otherwise your crock pot might crack due to the temperature difference. I use boiling hot water.
(10) Use a silicone spatula to mix the soap paste and the hot distilled water. Turn off your crock pot and cover it with the lid. In about 10 to 12 hours, your soap paste will be completely diluted.
It’s a good idea to use PH testing strips to check the PH-level of your diluted soap. You want your soap to have a PH-level between 8 and 9.
(11) Add about 25 drops of vitamin E to your diluted soap. Pour your DIY liquid Castile soap into a glass container.
That’s it! This is how you make your very own DIY liquid Castile soap. This is an all natural liquid soap that has many uses. If you use it for body or hair care, I would add 1 part of glycerine to 3 parts of DIY liquid Castile soap. Adding glycerine to the liquid soap will make it more moisturizing, less drying. If you want to use the DIY liquid Castile soap for cleaning or to do laundry, you can use it without adding anything else. If you want to add a natural scent to your DIY liquid Castile soap, you can add lavender essential oil or lemon essential oil. This DIY liquid Castile soap doesn’t need curing. But if you leave it alone in a glass container for a few weeks, it will become more transparent, and even more mild, with a lower PH-level.
So, will you be making your own Dr. Bronner’s inspired DIY liquid Castile soap? I’d love to know how you like the recipe. As always, if you like this DIY liquid Castile soap recipe, please pin it and share it!
I fear that I’m going to complicate things a ton. My ultimate goal is to make a body wash for My keratosis Pilaris. I want to include glycolic and salicylic acid. My first thoughts were to mix already made Castile like dr. Bronners with water + glycolic acid then combine that further with a glycerin + salicylic acid mix. I’m new to this as you probably can tell. I’ve only ever mixed up diy hair masks. Anyways now I want to make my own Castile but with olive, coconut, tamanu, avocado and jojoba oil. Deep breath so I guess I’m asking how would I go about combining all of this. Can I add a preservative like optiphen to the mix since there will be water? Also are EOs and fragrance oils added at the step where you added vitamin E or do you recommend adding those per small batch of body wash? Hope this all made sense Thxs!
Thanks for reaching out, Melissa! I don’t know much about keratosis pilaris and haven’t added glycolic acid or salicylic acid to my soap. I’m not too helpful in those areas. I can help with making liquid soap from scratch though. You can try my recipe posted above, or you can come up with your own recipe. Based on the oil you mentioned, I suggest using 55% olive oil, 30% coconut oil, and 5% tamanu, avocado, and jojoba oil each. You can use a lye calculator to figure out how much lye and water you’ll need for your recipe. I don’t use synthetic preservatives in my soap, such as optiphen, and depending on the pH level of your liquid soap, you probably won’t need it. Also, I prefer essential oil over fragrance oil, and you can add either after you’ve diluted your liquid soap. I hope I’ve answered all your questions. Please feel free to reach out if you have more questions. Happy soaping! 🙂
Is your dilution water by weight as well or is it fluid oz?
Great question, Brad. Step 9 of the instructions above says to add 34 oz. That 34 oz in weight, which I measured using a digital scale. I hope you’ll give this liquid soap recipe a try, and please feel free to ask any more questions you might have.
Hi,
Loved your post! I live in India and we do not have easy access to crock pots here and most of the cooking is done on a gas stove. So, is there any alternate to crock pot? Can liquid soaps be made using anything else?
Thank you for reaching out! I’ve not tried making liquid soap on a gas stove. It might be possible if you are able to keep the temperature of the soap constant while cooking. Be sure to monitor the cooking process closely to prevent the soap from boiling outside the pot.
As to your second question, some people make liquid soap by melting shredded soap bars in hot water. I tried that, but didn’t like the consistency of the liquid soap made from soap bars. Please let me know if you have more questions. And please keep me posted on your soap making adventure!
Hi!
I’m looking to use Dr. Bronner’s Castile liquid soap in a DIY shampoo concoction. I bought all the necessary ingredients, then upon further research learned that it’s really not good to use a Castile soap shampoo, which as a pH of 9+ and then use an ACV rinse with a pH about 3. I’ve read that this drastic change in pH can have negative effects on your hair in the long run. Even using a high pH shampoo without the subsequent ACV rinse is bad. Do you know of any shampoo recipes using Castile soap that have a pH of at least around 8 or lower so we’re not damaging our hair? Or, does this DIY olive oil soap have the same pH of Dr. Bronner’s or less?
Oh, good questions. Natural liquid soap, Dr. Bronner’s or a DIY one, could have a high pH level. One way to lower the liquid soap’s pH level is to add water. Maybe add 1 part of soap for every 2 to 3 parts of water. You can also add liquid oil, like olive oil, to make the liquid soap less drying. I think it’s the additional olive oil in Dr. Bronner’s Baby Unscented Pure-Castile Liquid Soap that makes it gentler than Dr. Bronner’s regular liquid soap.
I don’t generally use liquid soap on my hair. Instead, I use a shampoo bar, like this one, which has a high super fat content and is gentler on my hair. I don’t use a ACV rinse. Maybe a shampoo bar might be an option for you? I hope the above helps. Please let me know if you have any more questions.
Hi there! Love your recipes! I am a little confused though, is your measurement (oz) in weight or in volume (fl oz)? Thanks.
Oh, sorry for the confusion, the ingredients are measured in weight. A digital scale comes in handy when measuring the ingredients. Please let me know if you have more questions. I hope you’ll give this recipe a try!
Hi Silvia, thank for the great article.
Dr. Bronner’s soap recipe use Citric Acid while you do not.
What makes the difference?
What is the purpose of Citric Acid for liquid castile soap making?
Thanks for the enlightenment.
-dia
Great question! Citric acid is used to naturalize excess lye in liquid soap. Unlike bar soap, liquid soap is made without super fat. And sometimes it’s made with more lye than necessary. Most likely that’s the case with Dr. Bronner’s liquid soap, and that’s why you see citric acid as one of its ingredients. Please let me know if you have more questions.
Do I have to use coconut oil, can I replace it with another oil instead?
Yes, you can substitute coconut oil for another oil, such as olive oil. If you do that, be sure to run your recipe in a lye calculator (setting superfat at zero) to figure out the amount of lye (potassium hydroxide, KOH) that you need. My favorite online lye calculator is SoapCalc. Please let me know if you have any other questions. Keep me posted please.
Hi great recipe, can you please explain why only potassiun hydroxide and not sodium hydroxide is used to make the liquid soap. Keep up the great work!
Great question! Liquid soap is made with potassium hydroxide (KOH) because it makes water soluble soap (dissolves in water). Bar soap or hard soap is made with sodium hydroxide (NaOH) because it makes soap that’s less water soluble. Hope you’ll give my soap recipes a try!
Hi just wanted to check after i use the crock pot or any other stainless steel pot for soap making can i cook food in it ? If yes what should i make sure i do.
thanks
gracy
Great question. I separate my soap making items with my food preparation items. I get many of my soap making tools, like my crock pot, from a thrift store for a few dollars a piece. I think that’s what most soapers do. Please let me know if you have any other questions. Thanks for reaching out, Gracy!
Hi Silvia,
Just come across your post – love it, thanks for sharing!
I really want to make this as I’ve recently started experimenting in natural products and i’m in the middle east where there’s not a lot of choice about. I actually have potash feldspar (K2O) in my possession as a potter, but this isn’t the same as potassium hydroxide (KOH) is it? I tried to google it but it’s not clear. These kind of ingredients are pretty impossible to find here. Any ideas?
Thanks a lot
Hi Heather, I haven’t heard of anyone using potash feldspar to make soap. I don’t think it’s the same as potassium hydroxide (KOH), which is what people use to make liquid soap. I get my KOH and most of my soap making materials online (from Amazon), because they are not often available in stores. In my post, I included Amazon links that will take you directly to materials that you’ll need for this liquid soap recipe. Hope you’ll give the recipe a try!
How long does this last without any preservatives added to
It?
Great question! This DIY liquid soap recipe includes Tocopherol (Vitamin E), which is an antioxidant that helps to slow down oxidation. I’ve used liquid soap I made 6 months earlier, and found it as good as when I first made it. I think as long as you use it within 6 months, you should be fine.
Hi,
I would like to know how you came up with the estimated percentages for Dr. Bronner’s liquid Castile soap. I love detailed (and a total nerdy) explanations on percentages! Thanks for your time and willingness to share!
Great question! I made the educated guess based on the order that the ingredients (oil) are listed on Dr. Bronner’s Fair Trade & Organic Castile Liquid Soap bottle. Federal laws require companies to list ingredients based on their amounts in a particular product. This means that Dr. Bronner’s Castile Liquid Soap contains more coconut oil, which is the first ingredient listed, than any other oil. Likewise, it contains the smallest amounts of hemp oil and jojoba oil as compared to other oil.
Although under my theory above, Dr. Bronner’s Castile Liquid Soap could contain 50% or higher of coconut oil, I doubt that’s the case, because soap made with a high percentage of coconut oil is very drying. So, my educated guess began with 35% coconut oil (which is a typical coconut oil amount in soap) and I worked out the remaining percentages from that initial guess.
I’d love to know what you think. Maybe you have a different theory on the amounts of oil used? Please share.
Hi! I agree that a soap with too much coconut oil can be drying. Just curious though, doesn’t your recipe have about 62.5% coconut oil? Have you found it to be drying? Thanks!
Very good question! In general, high coconut oil content can make the soap drying, especial for hard soap bars. For liquid soap, it’s less of a problem, because you can dilute the soap with water to cut down its drying effect. Also, you can add a little bit of nourishing oil, like jojoba oil, to your liquid soap to make it less drying. Please let me know if you try this recipe, and how it comes out.
And just curious, how thick does this soap come out? Is it just a tad thicker than water consistency–similar to Dr. Bronners?
Yep. That’s right. It’s definitely thicker than water. The great thing about making your own liquid soap is that you can make it as thin or thick as you want depending on how much water you add during the dilution part of the soap making process. In fact, I usually further dilute the liquid soap before adding it to a pump bottle. Please let me know if you have other questions.
Would this end up being cheaper than from the store?
Yep, I think making your own DIY liquid Castile soap can be cheaper than buying it from a store, especially when you make big batches, and buy your ingredients in bulk. Another great reason to make your own DIY liquid Castile soap is that you can customize it to your personal preference. Hope you’ll give this recipe a try!
I love what you stand for on your blog, but it’s a shame you lump Dr. Bronner’s and by association Natural Habitats (2 of the planet’s most exemplary companies) into the same pile as RSPO certified palm oil – they are very different. This is a good read http://www.foodnavigator.com/Market-Trends/Good-palm-oil-is-possible.-This-is-what-it-looks-like-says-Palm-Done-Right-CEO
Thanks for considering this! In no way do I endorse conventional, or even RSPO palm oil, but it is important people understand what companies such as Dr. Bronner and Natural Habitats stand for, and are actively doing, to help make this world a better place. Thanks!
Thank you for sharing your thoughts. I must admit, I didn’t know about Palm Done Right, or Natural Habitats. I’ll be looking into both in the next few weeks or so, and report back. Thanks!
Thanks Silvia for your willingness to look into this – I could give you some more links, but you can do some independent research which will be more convincing! Companies like Natural Habitats and Dr. Bronner’s are examples of proactive companies doing wonderful things for the planet. If only more companies were just a tiny bit more like them …..! You already know Dr. Bronner’s is great – so it doesn’t make sense does it, that they would use unsustainable palm oil in their products – why would they when that would go against pretty much everything that they stand for?! They are fascinating companies that well deserve us all to sing their praises! Yes, I am obviously a fan! 🙂