Hot Process Soap

Basic equipment needed before you start

Scale (to weigh oils & lye)

Heavy Plastic Bags or Butchers Paper (to cover work area)

Soap Molds or Boxes

Vinegar (for safety to neutralize lye burns)

Thermometer (I love the Raytec Digitals)

Heavy Plastic or Glass Measuring Cups

Heavy Plastic Ceramic or Glass Mixing Bowls

Rubber Gloves (a necessity)

Eye Protection (good idea when mixing lye & water)

Face Mask (use when mixing lye & water)

Pot Holders (if handling hot crock pots)



Stick Blender (you’ll save yourself hours of hand mixing)

Recipe (2 pounds of soap):

Olive Oil – 6 oz.
Coconut Oil – 6 oz.
Palm Oil – 9.5 oz.
Sodium Hydroxide (Lye) – 3 oz.
Water (prefer distilled) – 8 oz.
Fragrance Oil – 1 oz.

Step 1:

Before we begin, you want to make sure you have everything you need at hand because once things get going you will not have time to go looking for stuff.  Do not use anything aluminum for soap making.  Aluminum and lye are NOT friends!  Using aluminum will cause your soaps to turn out ugly and tarnished.

Step 2:

Turn your crock pot on high, weigh all your oils and put them in your crock pot to begin melting. Put the top on the crock pot and wait about 10 minutes.

Step 3:

While the oils are melting, put on your rubber or latex gloves and face mask. Use the plastic or ceramic bowl to weigh your lye. Next use your glass pyrex cup to weigh your cold water (I use the glass because it can withstand high temperatures).

Next pour your lye SLOWLY into the COLD water while stirring. THIS IS VERY IMPORTANT. PLEASE, PLEASE, PLEASE, do not pour your water into your lye.  The lye water will heat up and get near 200 degrees so please use cold water. The lye/water will also produce a fume that may make you cough.  Be sure to be in a well ventilated area (outside is perfect).  You will want to stir long enough for the water to be almost clear again, it will be kind of cloudy, but all the lye needs to be dissolved.

Step 4:

Now you don’t have to wait on a certain temp, just pour your lye/water mixture into your crockpot with the oils. Take out your stick blender and blend. You will just stir with your blender for about 5-10 minutes, or until you reach trace. Trace is when your oils and lye are mixed and it starts to thicken up and look like vanilla pudding.

You will know when you have reached trace when your stick blender leaves droplets of soap on top and the soap is not thin and runny anymore.  It will look like pudding at this phase.  This is a thick trace. You will be able to make patterns like this.

At this point you put the lid on the crock pot and let it cook for a few minutes.  *Note: Removal of gloves and/or mask is optional. You should continue to proceed with caution, as spattering can still occur and can result in serious injury. Always use caution when working with lye.

Step 5:

Now we get our colors, herbs and fragrance ready but do not add them to your soap at this point or they will cook. I use the ceramic bowl for this. I use mica or candle block color for my soaps. I haven’t broken out yet, so they seem fine to me. I shave some in the bowl and measure the FO according to the recipe. Use about 1 heaping tablespoon full of dried herbs per lb. of soap. Using too much herbs will make your soap break apart easier and not last as long. Always use dried herbs or your soap may mold from the water content in fresh herbs.

Step 6:

It has been about 5-10 minutes, back to our pot – it’s thicker and the oils may have started to separate and go to the top of the pot.  

Step 7:

10 more minutes pass and now we’re cooking! Now the oils are starting to separate and its breaking up again. You just stir this down and put the top back on. Don’t leave!  Your soap will look like applesauce

Don’t leave your soap alone for too long. If you wait too long to stir, your soap will grow and overflow out of your crock pot.
So, just keep stirring every couple of minutes.  After stirring for a few minutes you should get something looks like applesauce and the soap will be gel like.
Keep stirring and your soap will change to the consistency of mashed potatoes.  Turn off your crock pot and use pot holders to take the ceramic part out of the heated base.
Keep stirring and in less than 1 minute you will have thick mashed potatoes.

Step 8:

At this point add your FO, herbs to the pot and mix well.  If you are using color, then take out a big spoonful and put it in the ceramic dish with the color and mix with a whisk or stick blender.  When the color is mixed well add the colored soap back to your crock pot and mix well until blended.  Or you can just marble the color through for a different effect.

Step 9:

Scoop out your soap and plop it in into your mold or lined box. A little hint, if you plan on using bakery stuff, please use pam in the bottom or some sort of bakers release, your soap won’t come out if you don’t. Don’t ask me how I know that either.  I always line everything with plastic or butchers paper.

Step 10:

After 24-48 hours – remove your soap from the mold, cut into slices if using a block mold and let sit for 2-4 weeks to dry out.  Your soap is no longer caustic and now you just want the water to evaporate out and your soap to dry out into hard bars.  Your soap is ready to use when the bars are hard.


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