Liquid soap using sodium hydroxide

I've been meaning to get some potassium hydroxide to make liquid soap.  I would like to make my own dishwashing liquid and also a liquid handsoap.  Both for me and my daughter who requested some.  The problem is, I have to buy another 25 kg of the stuff and truthfully, I think that really is overkill.  I just want to try the stuff, not set up a production line, for crying out loud!  So I always read a bit wistfully about liquid soap, the ingredients are basically the same and method isn't complicated.  It's just a question of getting my hands on a tiny amount of the other lye.

I've even thought about grating some soap and diluting it with water to see if that can be used in a soap pump, but never got around to doing it.  So I was thrilled when I came accross a recipe for liquid soap that listed good old NaOH rather than KOH as an ingredient.  I was a bit skeptical at first, thinking that it might just be a mistake.  It actually turned out to have been one, but it was explained that the writer had made the soap, both with NaOH and KOH and liked the NaOH better.  So I decided to go for it.

The recipe was on a website called The Little House in the Suburbs and it contained coconut, canola and vegetable shortening.  I fully intended to follow that to the letter (apart from the fuzzily defined vegetable shortening which I can't get here) but circumstance led me to have to devise my own recipe.  The only oil I had was a dark Olive oil so I used that and coconut oil.  The original seems to be pure white and I like that, so I will make another batch soon with white oils.  When I was going to make mine it was 3 o'clock in the morning and the internet wasn't working, I could only load Icelandic sites, but no foreign sites.  This was probably due to some Scottish farmer plowing his field and taking the cable in two (you'd think there were more sophisticated explanations to technological failures!).  So I couldn't use Soapcalc and I wasn't about to start to compute lye at that hour.  The solution was to use an old recipe and measure exactly.

The recipe I used was:
122 g /4.3 oz.  coconut oil  - 30%
298 g /10.5 oz.  olive oil    - 70%

250 g / 8.5 oz  water  -   this is quite a bit more than usual - about 60% of oil weight
56 g / 2.1 oz lye  - I allowed for about 5% SF - which might not be necessary in dishwashing soap.

The process is the same as usual CP.  When the oils and water have been combined the whole thing is insulated (I don't usually do that with CP) and left for 24 hours.  I put the soap in a large stainless steel pot and just shoved it in the cold oven and left it there.  The next evening I started to add more water to it.  A cup or so at a time up to 1.5 liter.  First I did this in the oven at a temperature of 105-120 C and stirred it in a little bit.  When it was starting to look liquid and smooth I put it on the stove and heated gently and added more water and stirred.  There was a bit of foam on the top, so I just skimmed that off and threw it away.  When I felt the soap was the right consistency I let the whole thing cool a bit and added lavender and peppermint EO and then poured it into bottles.

I like the soap.  It feels nice on the skin and it hasn't clogged the soap dispenser yet.  My daughter doesn't like the colour, but it's very olive-oil-soap-green so I figure that can't be bad.

Update:  I think this could be diluted a bit more.  I also put it much diluted into a foam dispenser and it works beautifully in that.  Soft, soft foam.  Much better than what was in there before.

The photo: I paid about 8$ for that candlestick and that is more than I usually spend but I liked it.  The tray is a dime a dozen used in catering quite a lot and I just love old terracotta pots.


  1. Oh wow, I have actually thought of doing liquid soap myself...but it looks so different that regular bar soap. I don't even know where I can find potassium...great work! I didn't have the slightest idea you can make it with old fashion lye. Tnx for the post and great job!

  2. i'm so pleased to have found your blog yesterday! i have been making soap only since the summer began, but have learned so much in the last 24 hours from you. i'm VERY excited also to have found such a simple liquid soap recipe now!

  3. Thanks for this- I guess you cooked it long enough for it to be cured?

  4. i have been looking for a formula to make liquid soap using naoh for a while, i just knew it was possible. naoh is so much more accessible and affordable than koh. i am so accustomed to making liquid soap using a hot process that i decided to do the same using naoh. i think it turned out great. thank you so much for posting.

  5. Thank you so much for the recipe. I will try it soon cause i can not find potassium easily here in Cyprus.(Minors used it to make crackers at easter- long story don;t ask). I've been trying to make liquid sope from my handmade castile bars, without success. I love my all olive oil soaps but they can not hold fragrance for long and its a mess to dilute them in water I don't recomend it.


  7. I just discovered your site!!! I'm really looking forward to exploring all the projects you've been doing - your creative energy is amazing and enviable!!!

    The liquid soap recipe is just what I need right now for some shampoo I've been making. I'd been taking the easy way out and using someone else's liquid castille soap, which is absurd given that I do my own cold and hot process bar soaps. Thank you for sharing!

  8. Jacki Ives - I actually have the same problem in the end. So I make a small amount each time. True liquid soap requires Potassium hydroxide which I don't have access to, so I haven't been able to try that process.

  9. Thanks for sharing, been looking for a recipe as straightforward as yours. You know you could also add 2 tbspn of glycerin to make it extra moisturising and tbspn of pure honey to preserve it longer. But about the color, I certainly would like to try to change it, any idea at what point I could do that?

  10. Thank you for the recipe. I have made a batch and I have found that every time I skim the foam off it keeps forming new foam. Has anyone else had this problem? Also I have found the soap to burn my skin.

  11. Anonymous - The foam seems to be unavoidable. Using KOH for liquid soap is really the proper way to make liquid soap. I just have no way of geting that and I did try to make do with sodium hydroxide. I solved the problem by using a small amound in a foam dispenser, but maybe one day I can make real liquid soap.
    But it was an interesting experiment for me :)

  12. by mistake the lady at the shop gave me NAOH instead of KOH, I made it as normal but my oil all caked up and became very dry, i had no idea what happened as all the way i thought i was using KOH. It was all dried and crumbled up even after 2 hours of cooking in my double boiler, so i just added lots of water and it turned out to be like a gel liquid soap. I absolutely love it. From now on I will make my liquid soap with naoh. Its like the consistency of store bought liquid soap. Love it Love it Love it!!!!


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