Home Made Liquid Castile Soap Recipe

Now that I made quite a few cold process soaps, I thought I should give making liquid Castile soap a try.

One can buy natural Liquid Castile Soap and use it to make hand wash, shampoo, face wash, washing up liquid, body wash by adding their favorite teas, oils, essential oils and fragrance oils.

how to make liquid vegetable oil soap at homeHome Made Liquid Castile Soap from Scratch. Great for using in home made shampoo and body washHowever, I didn’t want to miss on all the fun of making it myself for a fraction of the price so I went ahead, found some Liquid Soap recipes on the web, compared them with what I have in my cupboard, and concocted my own Liquid Castile Soap Recipe. It turned out all right and the 36 hours invested in the process were well worth it.

I wanted a clear, thick liquid soap, with a rich stable lather that I can use as a base for many washing products in my household, hence I didn’t add too much essential oils, dilution water or super fating oils, So here’re the oils I chose for my home made liquid soap recipe.

I used the grams measurements and a digital scales for this recipe as I wanted maximum precision:

My Liquid Castile Soap’s INGREDIENTS:

For the oil mix:

  • 300 grams Olive Oil – because I have plenty, it’s cheap, creates a gentle soap, comes out clear in liquid soap making
  • 200 grams Sunflower Oil – for the same reasons as above
  • 100 grams Coconut Oil – because adds bubbling action to the soap and comes out clear in liquid soap making
  • 60 grams Castor Oil – because it is said to create and sustain bubbles, as well as being very nourishing to the skin.
  • 6 grams of – Sweet Almond Oil; Carrot Oil, Aragan Oil – simply because I have them in my oils collection. I added just a few drops of each.  

Total oil content: 666 grams

For the lye solution: 

  • Lye: Potassium Hydroxide – 140 grams
  • Distilled water – 400 grams

Testing the liquid soap for clarity after adding boric acid to the sampleTowards the end: 

  • Hot distilled water: 1000 grams or more.
  • Boric Acid: 30 grams (or less) diluted in 200 grams of hot distilled water (optional)
  • Essential oils: lavender, tea tree, oregano, grapefruit, lime, lemongrass (all of which have antibacterial properties)
  • Color – (optional)
  • Glycerin (may be needed for thickening)
  • Super fating Oils  (optional)



Patience, the basic CP soap making equipment, plus a crock pot or a large double boiler and maybe a potato masher.


  • Liquid Soap Making starts the same way as CP Soap MakingSet the double boiler on low heat. The water underneath will have to keep simmering for the next 4 hours (if you’re lucky)
  • Weigh and pour your oils. Start with the brittle ones (if any), when they’re melted, add the hard oils and when these are melted add the soft oils.
  • Put on the soap making gear
  • Weigh very cool distilled water into a large heat proof container.
  • Weigh lye into another container
  • Pour lye slowly and gradually into the water and stir until the lye is dissolved. potassium makes an boiling sound as it’s dissolving. This is normal. The lye solution will heat up somewhat. No need to wait for it to cool.
  • Trace in Soap Making. Looks like Mayonaise.Add the lye water to the melted oils gradually, stirring carefully with a rubber spatula to avoid splashes.
  • Blend with a stick blender for 15 minutes. The mixture will become thicker at some point, expect a longer trace time than in CP soap making. When trace is reached, use the stick blender a little bit longer. It will start to struggle. Save its life and continue with a spoon until the mixture becomes too hard to mix.
  • Stop stirring and put the lid on. Set the crock pot to cook on medium for 6 hours but stir every 30 minutes or so.
  • Making Liquid soap at home. How to mixDuring this time the soap will cook. It will transform and go through several “stages”
  • Use stainless steel, wood rubber or plastic mixing tools to stir through these stages. At some point a potato masher will be the most appropriate tool.
  • The consistency of the oil and lye paste in liquid soap makingThe stages that you may or may not notice are: Thick applesauce –
  • Cooked custard with small bubbles –
  • Mashed potatoes –
  • Chunky/creamy Vaseline –
  • Thick Honey.
  • At some point during this magic transformation, stirring will be tricky however turning the soap from the bottom of the pan shall be attempted at least)
  • My liquid soap paste didn't go translucentWhen the mixture becomes translucent, it’s time to test it to see if it’s ready. BTW, my paste after 7 hours of gentle slow cooking, didn’t get to the thick honey, translucent consistency so I decided to go ahead and test for readiness anyway. It passed the test so I moved on to the next stage.
  • gloopy paste in liquid soap making at home using a double boilerTake two parts of boiling water and add one part of your soap paste. Stir this sample soap, breaking it up and helping it dissolve in the water.
  • Once it’s completely dissolved (several minutes) check to see how clear it is.
  • Testing the liquid soap for clarity after adding boric acid to the sampleIf it’s just very lightly cloudy, that’s o.k. It may be your combination of oils. Also, the soap will “settle” after it’s finished and get even clearer. But if the dissolved soap mixture is milky or very cloudy, you didn’t cook it long long enough
  • Adding the distiled water to the liquis soap pasteTurn off the heat and transfer the mixture into a larger stainless steel pot if you think that adding the dilution water will cause the soap to overflow.
  • Pour hot distilled water into the mixture.
  • Stir gently, wait a bit, stir again with the aim of homogenizing the mix. It will not be easy. The gloopy paste will look like it may not even be water soluble. Don’t worry. It will dissolve when you’re not looking. Do your best at breaking out the paste in tiny bits and allow it to sit overnight.
  • Melting the soap paste in hot waterIn the morning stir again. There may still be some chunks that will melt away in the next step.
  • Image of the liquid soap chunks floating in the hot waterNeutralizing the soap.
  • Heat up the soap in your crock pot. Take out a small sample and add a small amount of the hot boric acid solution, mix and allow it to cool slightly. If your clear soap turns cloudy, you’ve added too much boric acid to the soap sample. Take this into account when mixing the boric acid to your pot of cooking soap. I halved the amount of boric acid required by my original recipe. My soap is still clear.
  • adding color and castor oil to the sample of liquid soapsuper fating liquid soap, test on a small sample before adding to the full batchNow it’s time to add the essential oils, extra fats, glycerin, color, etc.
  • test on a sample size before adding color to your soapRemember: whatever you add, test on a small soap sample first.
  • I attempted super fating my soap with carrot oil…. it’s supposed to be good for ya. It didn’t mix properly. Castor oil made my soap sample cloudy. Glycerin make the sample thicker – which wasn’t needed anyway. The essential oils made my batch of home made liquid soap, fragrant and long lasting.
  • How to make Thick Liquid Castile Soap at HomeI poured the warm soap in sterilized jars, put them under the sink and I am now waiting for them to age: one week (out of two) to go.


 Conclusion: It took a lot of patience but I’m now the proud owner of 4 large jars of clear concentrated natural liquid Castile soap with the consistency of honey that can be used to replace many store bought cleaning products. Stay tuned for the upcoming home made shampoo recipe.

Did you ever make liquid soap at home? Share your experiences so we can learn together.