Homemade Hot Process Soap Recipe (2024)

The million dollar question:

Do REAL homesteaders use crock pots and stick blenders?

Well, I’m still not exactly sure what qualifies a “real” homesteader, but I’m gonna answer that question with a resounding YES.

I have a deep appreciation for my stick blender. And my dishwasher. And my washing machine.

And I’m pretty sure Ma Ingalls would have loved them, too, if she could have fit them into her covered wagon.

So, why I am talkin’ ’bout appliances this fine morning? Because appliances have turned soap making, a once long and arduous process, into a snap. Making a batch of gorgeous homemade soap only takes about a 90 minutes, where it once took much, much longer. And I’m showing you the ropes today.

But first, let’s answer a few common questions:

But, do I have to use LYE for homemade soap?!

Yep. You do. Lye is a part of any true soap making process. The basic formula for soap is:

liquid + fat + lye

Lye produces the chemical reaction which turns fat into soap. Otherwise, you’d end up washing yourself with a big blob of animal fat, or coconut oil, or whatever. Lye is our friend.

A lot of people have a fear of lye– I know I did. But the truth is, if you take the proper precautions, there’s nothing to be scared of. (Kind of like our buddy, the pressure canner).

Hot Process Soap vs. Cold Process Soap

Hot process soap making (aka crock pot soap) and cold process soap making are pretty much identical processes. The main difference is that hot process soap allows the chemical reaction to complete immediately, while cold process soap allows the chemical reaction to happen over a curing period of six weeks.

I’ve used both methods, but I prefer hot process soap (crock pot soap) for the following reasons:

• I can use the soap the following day, no six-week wait. (I like instant gratification)
• I don’t have to find a place in my tiny house to cure the soap for six weeks, out of the way of kids and animals.
• It really doesn’t take much more time.

**UPDATE**Come to find out, even though I’ve been told forever how hot process soap is ready to use immediately, this isn’t the case. I have since learned from a few soap makers who shared their knowledge that while hot process doesn’t necessarily require a six week wait, you will find the texture and hardness of the soap improves after a 1-2 week wait time. So while you can use it right away if you want, it’ll be better if you still wait a bit.

The biggest downfall in regards to crockpot soap is that it produces a slightly less-pretty bar, with a bit more lumpiness on top. However, considering I’m mainly interestedmaking soaps for family and friends, and not becoming an artisan soap-maker, I’m totally cool with that.

What supplies do I need for hot process soap?

Not too many! But there are a few (inexpensive) items that will make your soap-making life a hundred times easier:

(some of these are affiliate links)

• Crockpot — I found an older crockpot at a yard sale for $5. It’s my official soap-making slow cooker
• Glass or Pyrex measuring cups and bowls — You’ll want to avoid metal utensils/dishes in your soap making process since lye reacts with some metals.
• A digital kitchen scale — Seriously. You’re gonna want one of these.
• A stick blender — Sure, if you’re super committed, you can stand there and stir your soap for a couple hours… I’m not that committed. The stick blender (aka immersion blender) makes it happen in mere minutes. It’s worth every. single. penny.
• Soap mold — For the longest time, I’ve used a simple cardboard box lined with parchment paper. Really, anything can work as a soap mold, including shoe boxes, loaf pans, misc. kitchen pans, Pringles chip tubes, you name it. As long as you can line it with parchment paper so you can remove the soap, you can use it. I recently splurged on a silicone soap mold from Amazon. It’s nice, but it’s not a necessity.
• Safety gear — This includes eye protection, gloves, and long sleeves, to guard you from the lye.

Hot Process Soap Ingredients:

• Lye — Sometimes you can find lye at your local home improvement store (usually in the plumbing section), but I generally have a very tough time sourcing it locally… I ordered my last bottle of lye online. Just remember, you MUST only use 100% pure lye (sodium hydroxide). Nothing else can be added.
• Fat/Oil — There are SO many different soap fat options out there, it’ll blow your mind. If you get on some of the fancy soap-making websites, you’ll find detailed recipes calling for many different types of oil or fat in each recipe.Since I’m not an artisan soap maker, I like to keep it simple. My soaps generally contain olive oil, palm oil, coconut oil, or tallow (tallow soap recipe), in various quantities. Each oil has different properties it’ll lend to the soap. The more soap you make, the more you’ll find out which oils you like to use best.
• Liquid — I usually use water in my soap recipes, but milk is also a popular option. If you are using water, make sure to only use distilled water. That way, you’ll avoid any potential issues with the minerals your tap water might contain.

Alrighty, enough talk. On to the recipe!

Basic Hot ProcessSoap Recipe (aka Crock Pot Soap)

(A note about amounts: This hot process soap recipe produces about 30 oz of soap. I chose this amount because of the size of my mold. However, you can absolutely play around with the oil amounts in any soap recipe, as long as you run the final amounts through a lye calculator to make sure you are using a safe amount of lye. I always, always run my numbers through the lye calculatorbefore I make any soap recipe)

• 10 oz olive oil
• 20 oz coconut oil
• 9 oz distilled water
• 4.78 oz 100% pure lye
• Essential oils for scent (optional)

Other Equipment:

• Digital scale
• Safety gear (safety glasses, long sleeves, gloves)
• Stick blender
• Crock pot
• Non-metal dishes and utensils

To begin, measure out the olive and coconut oil. Place the coconut oil in the slow cooker, and turn it on so it begins to melt. (If you want to speed up the melting process, you can melt it on the stovetop in a saucepan instead.)

As the coconut oil melts, measure out the other ingredients, weighing each and every one on the digital scale first. In soap making, we always measure by weight, not by volume.

I measure my water into a Pyrex measuring cup, and the lye into a small glass bowl. Make sure you have your protective gear (eye protection, gloves, long sleeves) in place before you start handling the lye.

Once the coconut oil has completely melted, add the olive oil to the crockpot and allow it to mingle and warm up.

Now it’s time to mix the lye and the water. Make sure you do this in a place with plenty of ventilation, as the lye will produce a reaction with the water and emit fumes. I prefer to do it outside, or under my stove hood with the fan on.

Slowly add the lye to the water, as you continually stir the water. The chemical reaction will happen quickly, and the mixture will heat up, so make sure you don’t grab the water container without gloves or an oven mitt.

**Important** ALWAYS add the lye to the water. NEVER add the water to the lye. Adding water to the lye can result in an unpleasant Mount Vesuvius type of reaction…

Once the lye is completely dissolved into the water (you’ll want to continue to gently stir until this happens), add it to the melted oils in the crockpot. Do this slowly, all while stirring the soap mixture.

Now, grab your stick blender. Stir and mix the mixture with your stick blender. I don’t run it continually, but rather pulse it for short spurts, stirring the mixture as I go. You’ll see it blend together rather quickly and it will thicken.

We’re looking for it to come to “trace.” You’ll know this has occurred because your soap mixture will have the consistently of pudding, and will hold its shape when you plop some on top. Like this—>

Once trace has occurred, the hard part is over! Simply place the lid on the crockpot, set the timer for 50 minutes, and allow the mixture to cook on LOW.

While you don’t need to necessarily babysit the crock, you will want to be semi-close to make sure it doesn’t bubble over. Mine always tries to rise out of my crockpot at least once during the process, and I have to give it a quick stir to calm it down. It usually only takes once, though. Otherwise, you shouldn’t need to stir it.

While you’re waiting, line your soap molds with parchment paper (if you’re using a silicone mold, skip this step) and prepare any additives (see below).

Once the 50 minutes has passed, it’s time to test the soap to make sure the lye has reacted with the oils completely and no longer remains in the mixture.

I like to do this by grabbing a small amount of the soap mixture, allowing to cool for a second, and then touching it to my tongue. If it “zaps” me, I know there is still lye remaining in the mixture and it needs to cook longer. If it just tastes like soap,we’re ready for the next step.

If you are mixing in any additives, turn off the crockpot and allow the mixture to cool briefly before mixing in any essential oils. However, you can’t wait too long, as the mixture will begin to set up, so watch it carefully.

Pour the soap mixture into the mold, making sure to press it into all the corners and smooth out the top as much as possible.

Set it aside for 12-24 hours, or until it sets completely. (Usually, overnight is plenty of time).

Remove the soap from the mold, cut it into bars, and allow it to dry for another day or so to allow it to harden up a bit.

Now it’s ready to use. You made soap! Can you believe it?! You’re officially a homesteading rockstar. 🙂

Notes:

• While I use high-quality olive oil and coconut oil in my cooking, I don’t feel bad about using the lesser, cheaper grades for soap making.
• I won’t go into all the details of additives in this post, but some folks like to add things like coffee grounds, dried herbs, or ground oatmeal to their homemade soaps. Essential oils are also a fabulous addition if you want your soap to smell purty. You can also purchase colorants and dyes, but I never use them. I’m fine with naturally-colored homestead soap.
• One of the benefits of hot process soap is that there should not be any lye remaining on the crockpot or soap molds. This makes clean-up easier. However, to clean the lye bowl and stick blender, simply allow them to soak in a mixture of hot, soapy water and vinegar. The vinegar will neutralize the lye, and ensures you don’t burn yourself while washing them later.
• This recipe is 5% superfat. This means that we added extra oil to make sure the lye would have a complete chemical reaction, so it would no longer remain in the finished product. This is why it is so important to run all your soap measurements through a lye calculator first. Otherwise, you could potentially be making a recipe with an insufficient amount of oil, which can result in unreacted, caustic lye remaining in your bar.
• I like to scrape the leftovers from my crockpot into a small ball and use it right away while the bars are setting up.
• The sky’s the limit when it comes to the essential oils you can use in homemade soap! However, my current favorite addition to this recipe is 30 drops of patchouli and 20 drops of wild orange.
• Don’t expect a super strong-smelling bar of soap unless you add copious amounts of essential oils to the recipe. (I’m talking, like, a LOT. Way more than 50 drops.) Another option is to purchase specialty soap scents/fragrances. I personally limit my oil usage to about 50 drops per batch because I purchase high-quality medicinal-grade oils and I don’t want to use an entire bottle in one sitting. A lighter-scented bar is fine with me.
• You don’t have to make a soap recipe with multiple types of oil. You can definitely just use one type of oil if you wish. Pure olive oil soap will be very hard, as will pure tallow soap. Pure coconut oil soap has a lovely lather. Experiment and find out which oils you prefer.

More DIY Cleaning Recipes:

• Tallow Soap Recipe
• Homemade Pumpkin Soap Recipe
• Homemade Liquid Dish Soap
• Homemade Laundry Detergent