Hot Processed Soap Making Fun

Well I know I’m feeling better because I had the desire to make some soap over the weekend for fun! I needed some soap for my family and I like to use this opportunity to try out new recipes. I also did not want to wait for the cure time so I decided to make hot processed soap in the crockpot.

There are 2 ways to make soap. One is called cold process and the other hot process. Here is the difference:

Cold Processed (CP): This method involves combining your liquid/lye mixture with your oils and stirring until the mixture thickens (also known as “trace”) . Then pouring the mixture into molds. In a day or two you unmold, cut the bars and let the soap lay out on a flat surface to cure anywhere from 3 to 6 weeks depending on the recipe. This ensures the soap is free from all traces of lye.

Hot Processed (HP): You follow the same procedures as CP but instead of pouring into your mold you keep cooking the soap. The soap is heated and cooked all the way through to the end (meaning there is no traces of lye left in the soap). After you remove it from the mold you can cut the bars and pretty much use them right away. Although the bars can still be a bit soft so letting them sit for a week or so can harden up the bars as excess moisture evaporates.

I have always used the cold processed method (for the soaps I sell) for many reasons (the soap is smoother in texture, looks nicer, essential oils are easier to add, etc..). But every now and again I like to have a little fun time with my soap making.

If you are not familiar with making soap you will want to make sure you are prepared with information and the proper equipment before you start. I don’t go into a lot of that in this blog post mostly because I already have a few web pages on making soap ( ) and an entire ebook on how to make cold process soap, step by step filled with pictures and information ( ) … so this little tutorial is showing just the basics of what I did. Please be knowledgeable on proper soap making procedures and cautions concerning the use of lye.

My soap recipe is a 4# batch (that is the weight of the oils). I don’t recommend any bigger batch in 6 quart crockpot. You won’t have room to stir.

Here was the recipe I used…
18.9 oz coconut oil
30.8 oz olive oil
14.2 oz palm oil

20 oz water
9.2 oz lye

2.5 oz fragrance oil

The first thing I did was measure out my oils and my water…

Then measured out my lye..

I put the oils in the crockpot and set the crockpot on low, put the lid on and let the oils melt. Then I mixed the lye into the water…

After the oils were melted it was time to pour the lye/water mixture into the oils. With hot processing you don’t have to have your oils and lye at a certain temperature…

I started out stirring with a spoon then switched to a stick blender. I mixed the soap until it reached “trace”. Trace means the soap is the consistency of thick pudding. When you lift the stick blender out and drizzle a little of the soap across the top it will leave a trail for a few seconds before it fall back into the mixture. ..

This soap recipe traced really quickly. I put the lid on let it sit for about 15 minutes. When I came back the soap was starting to gel. It will go from the thick pudding to a gel like substance (again it happened pretty quick with this recipe). I stirred it around (or I should say my daughter did as it was very thick and hard to stir for me and my healing hand). In the picture you can see the white looking soap and the gelled bits mixed around..

It did not take long for all the soap to gel (this is the chemical reaction of the oils and the lye mixing and these are the stages it goes through to become soap). At this point it looks a lot like applesauce (and is much easier to stir)…

I put the lid on and let it cook for another 5 to 10 minutes. Now it begins to look a lot like waxy Vaseline. It has a shiny look to it (that look was hard to capture in a picture)…

At this point I took a bit and rubbed it between my fingers.. it felt like soap. Then I put a tiny bit on my tongue.. if I feel a zing to it, then there is still lye left and it needs to cook longer. If I don’t feel anything then that means that all the oils and the lye have converted to soap (and there is no lye left). I did not get any zing so I took my crockpot out of the base (if you can’t do this with your crockpot, then turn it off) and added my scent oil and stirred it around until it was mixed in well…

Now comes the experiment part.. I was trying to color my soap. I don’t normally color it. I wanted to try a more natural way to color it. So I added 2T of paprika. I was aiming for a peach color to my soap (I scented it with a fruity smelling fragrance oil)…

In the end it came out more of a tan color… oh well.. I just had to give it a try and see what would happen. Then it was time to put it in the mold. The soap is very thick and kind of plops into the mold. You have to work fast as the soap hardens up quickly. I put the soap in and would press it down with my hands and tap the mold on the counter to get out any air bubbles.. For this recipe I used a 4# wooden loaf mold that I lined with a plastic bag…

The next morning the I removed the soap from the mold..

And cut it into bars…

I have 10 bars that are about 5oz’s each in size. It has now been 2 days since I made the soap and it is hard enough to use.

An important note:
It is very hard to use essential oils with hot process soap. All scent oils (essential oils & fragrance oils) have a flash point temperature. This is the temperature that the oils will evaporate into thin air. Essential oils have very low flash points. They are basically so low that the soap will be hardening up before you can mix the oils in if you wait until the soap is the right temperature. Fragrance oils have high flash points and this is not a big concern. If you want to use essential oils I recommend you make cold process soap.

Happy Soap Making!!


  1. very interesting. Can you use your crock pot after making soap and what kind of fragrance oil did you use if not essential oil? thanks

    1. Joen, yes you can use the crockpot after making soap.. what you have in the crockpot when you are done is just soap.. so it was easy to clean! :) There are many more fragrance oils available than there are essential oils. I used a fragrance oil called, "Fruit Slices". Crystal :)

  2. Crystal,
    Your homemade soaps are the BEST!! I will be ordering more soon.

    Hugs to you my friend,

  3. Thanks. I am wondering the same sort of thing--can you use your stirrers and measuring cups, etc. afterwards for other things, or do you need to have separate dishes and such for soap making? I'm just getting into it, myself.

    1. Harleygirl... Yes you can use your things after making soap .. just wash them. I have separate things for soap making because I make soap to sell and it is just easier.. when I normally make soap for selling.. I make a LOT of it. Crystal :)

  4. Where do you order your lye? Dawn O

    1. Dawn.. on the link I provided above on soap making information I have a page on where to buy lye: I buy mine from the Boyer Corporation.. Crystal :)

  5. I am a Graphic designer who has been live Bangladesh and used Essential Oil Soap for many years. It’s protecting our skin. Its quality is a very nice. But its price rate is very cheap. Not only is it perfectly suited for your own skin, it makes for a wonderful gift as well.

  6. Thank you for all the blog posts! I love reading them.

    About the essential oils, I was taught (by a soap maker who is also a chemist) that the HP method preserves the quality of essential oils better than CP. Apparently with the CP method, the essential oils are more damaged by the saponification process. Do you know anything about this, I have been trying to do some more research. :)

    1. Interesting Marie.. my experience with essential oils and HP is that it is very difficult to get the temperature of the soap low enough before adding the EO's.. the soap starts to harden very quickly. If the temp is too high the EO's flash (meaning that they go up in a puff of steam.. ) when the soap is done there is very little smell left. I've had better luck with the fragrance oils because they have a much higher flash point.. I can get them mixed in before the soap hardens to much. Like I said .. this has been my experience with it..

      Crystal :)

  7. FOs aggravate my asthma (they're all by-products of oil refining), so I use EOs in my HP all of the time. I just make sure to have all three notes, top/middle/base to anchor them. I allow it to cool down a bit. I can still glop (or pour if I superfat a little more at the end) and mold at 130-150. I allow my honey ones to actually cool down to 127 before adding it, because it keeps the enzymes active in the honey. I do add a little extra shea butter at the end to keep it from "seizing up. CP soap still gets hot during saponification.

    My current Lemongrass Sage Citrus is still smelly (best seller, but my least favorite) after 4 months. It's sitting in my mom's bathroom for to make it "smell pretty". Hopefully, that helps others.

  8. I use EO in hot process, even citrus. I suspect with shae butter at the end of the process. Then, I put my eo in as the shae butter is incorporating. It comes out beautifully. I think both fragrance oilsand essential oils hold up better in hot process. I also think hit process soaps are beautiful. There is something to be said for rustic beauty as compared to swirls of artificial dyes.


Post a Comment

All messages are moderated. After approval your message will be posted. Thank you for your comments!! Crystal :)

Popular posts from this blog

Canning Cabbage

Canning Chicken Noodle-less Soup

Dishwasher Soap Sub