Super Cleanse Scrubber Soap Made in a Crock Pot




About: Welcome! Pleased to meet you, I am Barb; a Maker. I have been making things AND explaining how to make things for as long as I can remember. I was all about DIY before it was a popular term. I absolutely lov...

I have not bought a bar of soap in the last 4 years! Once I figured out how easy it was I have been hooked. 'And it is sooo much better than the 'detergent bars that you get at the store! Making is soap is a little lesson in chemistry. My favourite have been a super cleansing 100% Coconut oil soap that I made in the crock pot. So just to improve on a good thing I've added a scrub-factor to make it even better! (You can just keep it simple too)

We have all read all the wonders of coconut oil and it adds a lot to soap as well. It has a super high cleansing factor and makes an amazing amount of bubbles.


Step 1: The Recipe

Imagine a world without soap! Soap is a wonderful reaction of Lye (sodium hydroxide) and oil. This recipe is an easy hot process type. Just like the olden days where they cooked the soap, this is ready soon after it comes out of the crock pot; yes another use for your crock pot.

There is a great soap making recipe resource online: a recipe calculator

It is very important that the recipe is right as you would not want any 'extra' unreacted lye in the final product as it will break up you skin, so being accurate and using weight to measure is an absolute must!

You can choose the types of oils that you would like to use in your soap, how much soap you want to make, and see results for factors like hardness, cleansing etc. There are a lot of good resources on this page as well.

Lye (sodium Hydroxide) can be bought at a local hardware store as it's used for unclogging drains since it reacts with grease. I am using only coconut oil here since it has such a high cleansing factor.

Super Cleansing 100% Coconut Oil Soap Recipe

  • 2.7 ounces of lye (by weight)
  • 6.1 ounces of Water (by weight)
  • 16 ounces of coconut oil (by weight)
  • 2-3 tablespoons of pumice or other scrub material (ground coffee, paprika, oatmeal, crushed walnut shells)
  • optional mica eye shadow for some extra colour

you can also add a fragrance oil or essential oil if you like.

Step 2: The Tools

This soap is a quicker version than the cold process type so it needs to be cooked in a crock pot. The preferred mixing tool is the immersion blender (do not use it for food afterward).

You will need:

  • a crock pot that will fit the required amount (I use a small one)
  • Immersion blender
  • Gloves, eye protection, long sleeves (for safety since working with caustic material)
  • heat proof containers to measure and mix in
  • digital scale for accurate weights
  • mixing/scraping utensil
  • knife to cut finished bars
  • **vinegar** to neutralize the lye in case of any splashes

Step 3: The Lye Mixture

This the part where you should be extra extra careful. Lye will heat up to crazy-high temperatures when combined with a liquid. Put on your protective gloves, eye wear, and long sleeves.

  1. Measure out the lye in a heatproof container.
  2. In a separate container, weigh the water
  3. Place the container under the fan vent or outside as it will make fumes once lye is added
  4. Slowly, in small increments add the lye to the water (NEVER add the water to the lye)
  5. Mix slowly so not to splash
  6. Keep adding until it's all been added
  7. Stir until all dissolved (it will be very hot)

Step 4: The Coconut Oil

  1. Weigh out the coconut oil and melt it in the microwave. It melts at 76 degrees so it will easily melt
  2. Add the melted oil to the crock pot

Step 5: Where the Magic Happens

Add the Lye mixture carefully to the coconut oil

It will require thorough mixing, which is best done with an immersion blender.

Submerge the blender to prevent splashing and pulse the mix

It will immediately start to react and thicken which is called 'trace'

Keep pulsing until it looks like it keeps it's shape somewhat. (this oil thickens to trace really quickly but they don't always do this depending on the oil)

Step 6: The Cook

Sine this is a hot process soap, it will need to cook.

To prevent too much water loss during the cook you may cover with some wrap. Bring it up to slight simmer on high setting and once you see it bubbling at the sides turn down to low (about 30 minutes depending on the crockpot)

Check often to make sure it is not cooking too vigorously. It will change from a 'mashed-potato-look' to a 'vaseline-like' look when cooked. To test the doneness, put a bit on the end of a spoon and do the 'zap test'; touch it to your tongue and if its tastes like soap it's done. If it zaps like battery then there is still some unreacted lye and it needs more cooking.

Step 7: Forming

Once cooked you can pretty well put it in any non-reactive container. I line the plastic container with some parchment for ease of removal.

It will harden quickly so take a small portion (about 1/4 to 1/3) and add the pumice or other scrubber material into it and mix well but quick.

Step 8: The Layering

I like the look of rustic soap

Spread the pumice mix into the bottom of the container and quickly add the other layers. I added a bit of eye shadow mica to give a thin line of colour as well as some cocoa powder.

Finish off the top with the remainder, forcing it down and banging it on the counter to release air bubbles.

Set it in the fridge until cooled, remove and cut into bars - I love this part! SO gratifying!

Step 9: Squeeky Clean and Fresh!

The cleansing factor for this soap is quite high so it will get off all that greasy paint and oil. Use the scrubber side to give some extra power for dried on dirt and grime, no need for a brush.

This recipe has such an amazing amount of bubbles, almost unreal! I've heard that it will even lather salty ocean water!

Since it is highly cleansing be sure to give your hands a treat of some nice handcream... or make some! For more soap and other DIY's visit

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    22 Discussions


    11 months ago

    There's no reason why you can't use the blender for food afterward. I realize you are speaking of safe practices, but there's nothing in here that is truly toxic. Lye is caustic, but not toxic and it will wash away. It's funny that you say that and then talk about tasting it. No, don't taste it !!!, if your measurements are off you could wind up with a nasty burn on an extremely sensitive area, use a pH meter or some other standardized testing technique. Refer to this article for details:

    5 replies

    Reply 11 months ago

    Yes, you are right since I did not use any fragrance oil. I'd not use it after fragrance oil though. I know lye is traditionally used in the making of the german yeast pretzels. They are dipped in a weak lye solution to get that dark brown crust.

    Thanks for the info in the PH testing. Funny how the zap test is quite an acceptable practice in the soapers world.


    Reply 11 months ago

    It does seem to be acceptable in common circles, but as a chemist, I highly recommend against it. If you get zapped that means you have destroyed cells. I like the cells on my tongue just the way they are.

    Best practice is to use a proven recipe, super fat by 5%, measure carefully and try it out on your skin. Don't risk your tongue cells. In the comments section of the article I posted one woman wrote that she had in fact hurt herself by doing it.


    Reply 9 months ago

    You add 5% of extra fat than it takes to theoretically react with the lye. This is a safety measure in case of errors in measurement or calculation. Since oils are a natural product the percentage of individual fatty acids varies. A little unreacted fat is not a big problem, but unreacted lye still present is.


    Reply 11 months ago

    Oh wow! I usually do super fat quite a bit and use Soapcalc. 'Did not know I'd get damage... Chemists are always handy! Wish I had one!


    Question 10 months ago on Introduction

    Just tried this for the first time and it went well except for that it set up so quickly out of the crock pot that my bottom layer dried too fast for me to spread it. I'm talking seconds. The soap turned out pretty but crumbles in between the layers. Any suggestions? Thanks!

    2 answers

    Answer 10 months ago

    Wow, I have not had that happen with my 100% coconut oil soap. Are you sure it did go through the 'vaseline like' stage? Did you do the zap test? Maybe the coffee etc did not get combined well and created a place to break. If it has saponified then it is still good soap. You can do something with it if you like. Soap can be rebatched in a crock pot too. You could cube this soap and then make another batch and add these cubes when the new one is done. Or you could just rebatch it all but then it will prob look ugly as it will all mush together as one colour. That is the beauty of soap making; it can always be reinvented. Perhaps it needed more water as it cooked out to much. More water can be added even at the end as long as it is stirred in well. I wonder... if you rebatched a small amount and then used it like a glue to attach the layers? Rebatching is easy; cutting or grating up the soap and then adding water or milk and slowly softening it again in the crock pot. Just don't scorch it. A bit of extra oil can also be added to make it more conditioning. It does look like a nice white/dark chocolate bark!


    Reply 10 months ago

    thanks for the quick reply! I made a second batch today and it turned out much better. I do believe the coffee was the culprit. This one has lemon and lime zest, and lemongrass and lavender scent in it. What a great recipe, thanks!


    11 months ago

    I love this idea, but I'm totally addicted to liquid soap. Any idea how to modify this recipe to make liquid soap instead? I'm guessing just more water, but hey, what do I know?

    3 replies

    Reply 11 months ago

    No, do not add more water, use KOH instead of NaOH.


    Reply 11 months ago

    I am not sure which soap you are referring to as there is body wash type and then there is the clear kitchen type. The clear kitchen type is 'makeable' but it involves a different process (also a cook) and another lye. I have made it before but it still different than the kitchen soap as that is more of a detergent as are many of the 'body bars' nowadays. There are many good recipes/methods online. For body products you may try or for soap;


    Reply 11 months ago

    I also love liquid soap. I've never tried to make my own soap but I'd be interested to find out if this recipe can be amended to liquid. Then I'd give it a go.


    Answer 11 months ago

    Since this soap goes through a cooking stage the lye finishes it's reaction with the fats (oils). There is a well know way to test called the 'zap test'. You touch the end of your tongue to a tiny bit of the soap and if it zaps like a battery then there is still lye present. If it tastes like soap it is done. Soaping is an interesting hobby, and there are many options! I love my goats milk soap the best! but it needs the cure since it's a cold process soap. Soaps should be allowed to breathe and the actually get better over time as long as the oils used do not go rancid.


    11 months ago

    Great instructable! We're actually running out of kitchen soap in my I'll have to give this a go. I'm also interested in that stone soap dish you have, did you make that yourself?

    2 replies

    Reply 11 months ago

    Thanks! Having used that soap for quite a while now it is definitely a scrubber! The high cleansing factor of coconut can be made a bit more skin friendly if 'superfatted' quite a bit as much as 10%. It works up a thick lather like shaving cream in no time, no other oil does that! Yup, I made the soap dish too! I've always got many stages of projects; I hope I get it on my site soon! (lots of concrete casting)


    Reply 11 months ago

    You are really a wealth of information :) Looking forward to reading it!


    11 months ago

    oh I love pumice soap!! This looks like a great recipe.