Perfecting my Hot Process Soap Technique

One of the many cool things about making soap is that there are a lot of techniques to choose from.  I started out using the cold process method, but recently have been making all of my soaps a different way.  My now preferred method is a form of hot process, which is like the name implies, uses heat in the soap making process.  I wrote about this technique in an earlier post.  Some people think that the reason people do HP is that you can use the soap right away.  While that is somewhat true, the benefits for me are quite different.  Before I get into those benefits, I am going to share my exact process for HP because again, there are quite a few techniques to pick from.  I learned my technique from the amazing and talented Sharon Johnson so I in no way, shape or form came up with this idea.  I am just passing along the knowledge that Sharon was incredibly generous to share.  Here are a few soaps I have made with this process.

Sweet Orange Chili Pepper

Lemon Verbena

Black Raspberry & Pomegranate

A few things I would like to say before I walk through the process.

1. If you have not made soap before, I recommend getting a few basic soaps under your belt first.  Check out Soap Queen TV for a wide array of tutorials and recipes.  This technique only started really working for me once I understood what happens chemically during the soap making process and a few beginner recipes would be invaluable in gaining that knowledge and experience.

2. I am by no means an expert on this technique as I am still learning myself

3. Thanks to Sharon Johnson, Jami Summer & Katona Wright for sharing valuable knowledge with me about HP

OK!  Let’s get started.  This process starts out like regular HP – melt your oils in the crock and mix your lye with water.  I prefer to use 38% water, although others who use this technique like 40%. (note: one reason why this is not a beginner recipe – you would learn what the 38% means once you make a few batched).  With 40% my bars were too soft which may be a function of my recipe.  I recommend a recipe what generates harder bars but that is not completely necessary if you have a recipe that you like.

Before I start, I like to get all my colors, additives, mold & fragrance all set up so once the cook is done, I have everything handy.  When I have not done this, I have forgotten some of the additives like fragrance.

I like to let my lye water cool for about 20+ minutes because I think the soap cooks more gently.  When I have added very hot lye water to my oils, the soaps cooks very very fast and has become overcooked on a few occasions.  I stick blend the mixtures until it reaches light trace.

Next you “DITCH THE LID”.  That simply means cover your crock with plastic wrap.  I don’t remove the saran to stir.  I let it be until it does its thing.  I used to stir so I get why you want to do that.  I suggest that you don’t however as you will let the steam escape and lose some fluidity in your soap batter.

After the cook starts, I keep an eye on things.  See how the soap is starting to gel on the left side?  The soap always cooks from outside inwards because of where the heat it.  It can be hard to see in the photos because of the steam on the plastic wrap.

soap is starting to gel

I also check the temps.  I don’t want it to get too much over 180 (but that has happened and the soap was still ok).

Infrared thermometer lets you check temp through the plastic wrap. Almost to 180.

ok – here is where I take off the wrap.  It is almost done gelling but not quite.  The part in the lower middle is not done gelling but this is still where I stop this phase of the cook.

At this point I stir with a whisk and add my superfat, full fat greek yogurt (1T ppo), coconut milk (1 T ppo), sodium lactate (1 t ppo) and sometimes kaolin clay (1/2T ppo).  Whisk whisk whisk and then I put the actual crock cover on and wait a few minutes (3-5 but i am not always that patient).  This wait time converts the batter in a smooth, fluid, pourable soap!

Batter with additives but before 2nd mini cook.

Waiting during second mini cook

Fluid batter after 2nd mini cook. It is worth the wait!!

Now it is time to split up the batter, add color, wait a little and then add fragrance.

Below is my attempt at taking a photo pouring the batter into the mold. My batter is pourable but it is a different texture than CP so don’t expect it to be exactly the same.

I did not take any more photos while pouring the batter, but here is the mold full of soap!

I did swirl up the top a bit after taking this photo.  After this step, I let my soap sit for a while to cool and then pop it in the freezer for a few hours.

And then comes the absolute best part!!  The cut.

Note: I make sure to gently warm my yogurt and whisk it smooth.  Want to know why?  Because one time I did not.  Note the brown specks that are not supposed to be in this soap.

If you are still reading then you must be pretty interested in learning more about the hot process of soap making.

So why do I prefer this method over traditional cold process?

1. No worry about acceleration from a fragrance oil.  I still get very anxious when making a CP soap that when I add my fragrance it will accelerate trace and make my the pattern I have planned impossible.  Not an issue with HP because you add fragrance after the cook

2. Less morphing of colors.  Again, colors are added after the cook so they are not present in the soap when it goes through saponification

3. No worry about gel / partial gel / ungelled soaps.  All HP soaps go through the gel phase.  With CP I had quite a few soaps overheat because of additives such as honey and goat milk and the soaps had to be rebatched.  I also have had quite a few soaps go through partial gel which is again not what I wanted to happen

4. I control the superfat.  I like to use skin softening oils like cocoa butter and shea butter as my superfats in HP.  Because they are added after the cook, I know that they are not going to turn into soap.  With CP you have no idea which oils ended being the super fat.

5. The clean-up is SOOOO much easier with HP.  You are washing soap out of your crockpot and off your tools.  With CP everything is a greasy mess that never seems to actually get clean.

6. The cure time is sometimes less.  However, I still let my soaps harden for 2-4 weeks so that they last longer.

Do I still do CP?  Yes, I like to make a goat milk soap that is a nice creamy white and I have not figured out yet how to do that via HP (it turns a light brown from the heat) so I still make that soap using cold process.  I could just add a little goat milk after the cook but I love this soap made with 100% goat milk as the liquid so I would need to add it before the cook.

Thanks for reading!  Happy soaping.