21 June 2010

Soap making - deconstructed

I made a new batch of soap on the weekend.  It's the olive, rice bran, coconut oils mix I usually make but soap may be made with many different oil blends so be guided by a soap making book, if you have one, or any number of the excellent soap making sites on the web.  Once you find a blend that works well for you, stick with it; I am sure that soap will serve you well for many years.

Bowl of measured caustic soda granules.
One thing I always find when I write about soap is that while many people know how to make good soap, there are always a large number who want to, but hesitate, saying the danger or caustic soda is their stumbling block.  On Friday, Helen said that after googling caustic soda she found it is used as paint stripper so she doesn't want to use it.  Let me say this plainly: ALL soap, even the 'natural' soaps you might buy for five dollars a bar are made using lye or caustic soda.  You cannot make cold pressed soap without using lye or caustic soda.  Lye and caustic soda are the same thing and when they go through the process of saponification, they are neutralised and turn into soap.  I use Sodium hydroxide (NaOH) to make bar soap and Potassium Hydroxide (KOH) to make liquid soap - both substances are caustic.  I will write more about the small danger associated with making soap tomorrow, but for now, let's concentrate on the process.  The recipe I used and the process are the same as that in my tutorial, which is here.

Pour the caustic soda into the water, not the other way around.

I have broken soap making down into a few different parts:
  1. Preparation 
  2. Getting the temperature right
  3. Mixing
  4. Moulding
You need to prepare the area you'll work in.  Caustic soda can burn you, your bench tops or anything else it comes in contact with when it's wet.  The granules of caustic soda are fine until you add water, even a moist hand will start a burning reaction.  Please follow these steps:
  1. Open the windows to allow good ventilation.  There is a short period after you mix the caustic soda and water together when you will smell fumes.  Good ventilation is essential. 
  2. Make sure there are no children or animals around.
  3. Make sure you have a clean and clear area to work in.
  4. You'll need measuring jugs, a stainless steel, plastic or wooden spoon, candy or milk thermometer, saucepan, accurate scale for measuring your amounts, mixer or stab blender and your mould.
  5. Have everything ready and measured before you start.

Getting the temperature right
  1. To make soap you add water to a jug and add caustic soda to the water - not the other way around, it splashes too much.  As soon as you mix the caustic soda and water together they will start to heat up.  You don't have to add heat, the water and caustic soda alone create their own heat.  This mixture will heat up to about  80C/170F and after you mix it well so it's dissolved, you'll have to wait for it to cool down again.  Mix the caustic soda and water first.  You want the caustic soda and water to cool down to around 50C/125F.
  2. You also have to mix your oils together and heat them up on the stove.  Heat to around 50C/125F - you need the caustic soda and the oil to be around about the same temperature.  When they are, mix them together.  Pour the oil into your mixing bowl first, then add the caustic soda.
Have everything measured and ready before you start.
  1. Mix until you reach trace.  Trace is when the soap has thickened and when you drizzle the soap from the mixer onto the top of your mix, it will leave traces that don't disappear into the mix..
  2.  Mix gently at first until the oil and caustic have blended, then increase your speed.  Yesterday, my soap took about 10 minutes to reach trace.  The time will be different each time because it depends on the temperature and the oils used.
This is what trace looks like - instead of a smooth top, the ripples stay on the top.

After you reach trace, pour the mixture into a suitable mould.  It can be a plastic resin cake tin, such as the one I use, or small moulds for individual soaps, or a clean milk carton.  Don't use aluminium.  At this point, try to retain the heat in the soap by wrapping it up in towels.  It should be ready to unmould the following day and then you can cut the soap into the size bar you would like.
 Wrap up the soap in towels to retain the heat.

Soap making is a very useful skill that I encourage you all to develop.  Even though it has elements that might be dangerous, with care and concentration, you will be able to do it.  When you've made one batch, you'll understand the dangers and realise it's straight forward and easy, as long as you prepare well and follow the steps.  Tomorrow I'll be writing about how we have been removed from old homemaking skills and scared into believing we have to rely on commercial enterprises to 'save' us.  It's an important topic so I hope you'll come back to read it.



  1. I just failed at my first batch "crockpot" soap and was unsure why. I think your post explains it a little better. The instructions we used paid no attention to temperatures. We did not let the lye/water mixture cool, nor did we wrap our molds to retain heat. We ended up with an oily, gooey mess that burned our skin. Yikes! We will try again with your instructions. Thanks!

  2. This is a very helpful post Rhonda, thank you. I am one of those people who is nervous about making soap because of the lye, but I really think I should just give it a try, because I like to use only natural soap, and I don't want to spend $5 a bar any more!

  3. Hi Rhonda, we are anxiously awaiting using our first batch of soap and are going to get another ready so that we have a good storage of them and hopefully cut the next lot a little nicer lol but they look good already. Although it sounds a bit scary it is quite easy if you are sensible and follow your very easy instructions, we decided to add Lime fragrance to ours and could not smell it when we were cutting only to be told by the herbalist that you add this when it is quite cool as it burns away if you add it to the hot mix,would you agree or have you a time that you prefer to add anything to your mix.Thank you Carole

  4. I've never made crockpot soap. Try this method, it's easy.

    Laura, just do it. I'm sure that with care, you'll produce a fine batch.

    Carole, I never add fragrance but I believe you add it at trace - right at the end. You also need to add a lot of essential oil. Something like two tablespoons, I've heard. I hope your first batch is a good one.

  5. I too was scared of the "fumes" warning . So my first batch of soap was made with the front and back door open plus every window in the house when we had a howling southerly blowing. All went well and I realised my over caution was for nothing.
    I shared my soap with my craft group who all loved it and so we made it at craft - so easy and such gentle soap.
    Now we are making the liquid laundry detergent using the soap. One lady lives in a very "communal" street and she has all the neighbours making soap as well.
    It's spreading like crazy - many people are going back to do it yourself with your help Rhonda.

  6. I have never seen a plastic resin cake tin in the U.S
    Does anyone know where I can get one ?

  7. I really want to learn to make soap but, like some other things I want to try, it'll have to wait until the kids are bigger.

    I'll definitely be back to read your post about how we've been scared away from the old homemakings skills. I wonder how many people who are scared away by the soap ingredients are okay with home canning? We do things all day long that are potentially dangerous.

  8. Hello Rhonda, thanks for describing the soap process. I think it's very interesting too! Last year I made soap following your tutorial. It came out well, I'm using it all the time, but the rest of the family doesn't, because they prefer foamy and perfumed soap...

    In one of Laura Ingalls' books I read about soap making in the old days. They poured water in a bucket filled with ashes, with a hole in the bottom, and the stuff that came out from the bottum was used for soap, like we use caustic soda. And of course they used animal fat instead of vegetable oils. I wish we had a fireplace, for sure I would try this out. Unfortunedly the book isn't very specific on the amounts...

    Looking forward to you next post!


  9. Clarien, I'm pleased the soap is working well for you. What you described Laura doing was making lye from wood ash. It's how many of our ancestors made soap.

  10. Thanks for this post. I have been wanting to try soap making for some time now and I just need to get up the nerve to do it one day. I am sure I will be following your steps very closely. I have been using the hand made type soap for at least two years now and really like it and the bars seem to last a very long time.

    Thank you and have a great day.

  11. Morning Rhonda, thanks for another great tutorial. I look forward to the first time I make soap, hopefully with a few friends.

    In the meantime I have found a supplier of natural soap in Toowoomba, QLD: Amazing Soaps (from Pittsworth) who make a pure olive oil soap. I tried it over the weekend and it was lovely. I used it on my face (a first) and my skin is noticable smoother! I also tried it in my hair but felt it didn't work too well, I didn't follow with conditioner thinking that I'd use a little oil afterwards. Is it a case of 'it won't happen overnight but it will happen?' LOL

    I love the idea of only having a thick cake of home made soap in the shower, instead of the 5 commerical bottles!

  12. I have made my own soap for years and I love it. I can be creative and make whatever I am in the mood for. Your post reminds me that its time to make more.

    This year I am going purely organic and making my own organic soap colour.

  13. Ive just started using my firt batch of soap (the Goats milk & honey recipe from the forum) and I love it! It was a little daunting at first, but once I started the process it was pretty straight forward and relatively simple.
    My skin is very grateful! the last couple of weeks I had been using a commercial soap - my soap was curing in the shed and I kept forgetting to grab another bar until I was already in the shower. This morning I finally remembered and it was like washing myself in a soothing moituriser - ahhhhhhhhh, yes I love my soap and I will definately be making more.

  14. Do you need a large work area when making the soap? I live in a small apartment and was just curious how much space I should properly allow. Also, what kind of thermometer did you use for taking the temperature of the caustic soda/water mix and the oils? Did you use the same thermometer or seperate ones? This is really interesting.
    I started making my own laundry powder because it doesn't make my skin itch and turn red like store brands. As I was researching this, I found out soem interesting things about the history of "detergents" in the United States. Aside from that, I'm 30-something...but I lagree with your lifestyle of living simply and making things for yourself. I inherited much of that from my grandmother. she made the everyday things beautiful for me...and she wasn't even trying!!! It's just what I observed from her example. I love being able to make things for myself!!! Thanks for doing what you do... YOu are a wonder :) :) Greetings from Oregon,
    Heather :)

  15. Your tutorial -- the first step, about adding the caustic soda to the water -- reminds me of a ditty we learned long ago in chem class about adding bleach:

    Do like you oughtta
    Add the bleach (acid, caustic soda) to the watta.

    This helps me remember what to do. It's important because the dangerous substance is heavier than water, and if added first can slide out and splash you, and offers a larger surface area for the exothermic reaction that will take place (this is especially true with a strong acid). If you add it to the water, it sinks and there is less surface area for a reaction.

    It won't rhyme if you try to do it wrong! ;)

    Thanks for your encouragement!

  16. I have gone through your tutorial from the past and said this year I was going to try it. I must admit the chemical reaction scares me, but I'm sure I will manage fine.However I seem to have real issues trying to find the ingredients that you use. I shall keep up the search. You are a real inspiration.


  17. I am really keen to try out some soap now that I have some free time ! just wondering if you know if you should be handling lye/caustic soda if youre pregnant ?? Im aware of the precautions and not to inhale the fumes.... ?? cheers !
    p.s the pea and ham soup was fantastic !

  18. This is a great post and it's good to hear that you don't keep your soap making utensils separate, as it can be expensive doubling up on everything.

  19. Good Morning Rhonda! Thank you for posting this...my courage is rising! I am going to go for it once I source all the ingredients. :)

  20. what a brilliant website Rhonda, I love it. Can't wait to have a go at the soapmaking, your illustrated instructions are so good and explain everything so clearly. Just one thing, when I get to the blender stage...well, I don't have stick blender or a mixer...would a balloon whisk work just as well? Albeit taking a bit longer I suspect! Or could I just put the whole lot in my food processor..... or would it disintegrate if I did? Many thanks for such a great site,

  21. LOL! That's exactly the point I am at, being too scared to have a go. I've made the re-batched soap a couple of times and that was fun, but I would like to try the 'proper' soap-making one day.

  22. Hi Rhonda! Do you use the same mixer beaters and thermometer, bowls, etc that you later use for food? Or do you have soap making supplies that you use only for soap? I hope to try this soon!

  23. Hi, I just made my first batch of soap recently after being scared of lye for ages - and you're quite right, it was really easy and straightforward, and even though I didn't do everything perfectly it came out great (I think I used a good recipe). I'll be making my next batch this week, I'll never go back to commercial soap! I will read your tomorrow post because I suspect I'm going to agree with it :-)

  24. I am hoping to make soap soon. I make many of our own products now and I get such a lovely feeling when I'm done...I can't describe it. Something like confidence...security maybe?
    Anyways, I just have to convince DH to let me try. He says it's not worth it because we can get bar soap so much cheaper. We'll see!
    There are a few blogs I follow that have different naturally scented soaps- lavender, rosehips, orange zest and all that tricky stuff. It looks so fun!
    The Girl in the Pink Dress
    PS Where is it possible to buy coconut oil? I found it in a grocery store for $10.00 in a little wee container. I was hoping for a bigger size with a smaller price.

  25. I really want to make soap, but I have some reservations because I am pregnant and wondered if you know if it is unsafe because of the fumes?

    1. Kalli, I've made this soap when pregnant with no worries. I open the windows and have the rangehood fan on to be safe, but the fumes have never been overly strong anyway.

  26. I am slowly, but surely getting up the courage to try this! I would love to make this part of our every day living. Thanks for the great post!

  27. I used to make soap with my mom. Very enjoyable. The only thing I have against it is that I have a small kitchen and 2 small children. And plenty of other things I should be doing... One day I will take up this venture again.

  28. Thanks for the guidance.Sure it is dangerous and hard to do but it is worth when you have the soap home made and pure and organic.

  29. I am definitely going to try this! It is just making the time for it along with all the other 101 projects. Since we won't be moving anytime soon I have been taking everything out of pots planting, landscaping, etc.. All of this takes time, and I have to remind myself that with my first house when we moved from it to here I was there 18 years! I just can't get it done fast enough!!
    The one good thing is that hubby set up an outside stove for me so I think I'll be doing the soap making out there.
    It may be a little while, but I'll do it!!
    Now I'm going to check out your shampoo as I have learned store bought has engine degreaser in it!

  30. Thank you for generously sharing your vast knowledge. I purchased all the ingredients last winter after reading your soap-making tutorial but did not get up the courage to do it until this weekend. It went remarkably well and is currently curing. The additional information in this current post helps clarify a few things but it went much easier than I anticipated. Thanks you again! Celeste in Missouri, USA

  31. Thanks again for your soap instructions, Rhonda. I made my first soap last week and love it. Sadly, it has to cure for 2 months! I'd like to get to the point of selling small batches of soap at market, so i need a good recipe that doesn't cure so long and hopefully has easily attainable ingredients. I use all my own homegrown botanicals, but need to find good oils that are good for hte skin, a little more lather than glycerine. do you have any other recipes to share?

  32. May I suggest a couple of things. I make my jug of lye up in the kitchen sink. I figure that it can't be knocked if it's there. Laying out newspaper makes cleanup quick and easy. I always feed my children (youngest 4) before I soap and tell them they won't be able to enter the kitchen until I'm finished. They understand this and there's never been a problem.
    Go for it! Follow instructions and you'll be fine.

  33. I have a question ~ How do you get the designs on your soap? Is this in the mold itself or is it a stamp? I really enjoy your site and we have been enjoying living the simple life as well.


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