This Slow Cooker Hot Process Soap Recipe is a good first-timer soap recipe choice. The advantage of hot process recipes are that the bars are ready almost immediately, rather than having to wait the month or more before you could use Cold Process soap.
Why Make Soap?
Have you ever wanted to make your own soap? I love making my own soap several times a year. The reasons I make my own soap:
- After I started to use homemade soap, every other soap seemed so artificially-fragranced and I came to dislike how the fake scent from the lab-produced fragrance oil lingered uncomfortably on my skin
- Homemade soap has become my favorite small gift, either by itself or as part of a gift basket; people really seem to appreciate it and are amazed that you made it yourself
- I love watching the ingredients come together and turn into something special. It’s chemistry, but it seems like magic
- I love customizing base oils and essential oils to make special-purpose soaps
- I love how homemade soap smells, even before I add essential oils
- It’s really fun!
Making soap can seem very intimidating at first, but it really is doable once you have the right equipment and follow some simple safety rules.
Simple Soap Safety In a Nutshell:
- Dress in old, long-sleeved, leg-covering clothes and perhaps an old apron to cover your skin and protect you from splatters
- Use rubber gloves
- Wear safety glasses
- Maintain good ventilation (your stovetop vent hood, a small fan, or an open window is good)
- Keep small children and pets out of the area while soaping
- Set up your equipment and supplies before you start and read all instructions before you begin
Hot Process Soap Recipe
- 36 oz. olive oil (emollient and gentle)
- 6 oz. coconut oil (helps make a good hard bar)
- 3 oz. castor oil (improves suds)
- 6 oz. lye
- 12 oz. water (I use 100% sodium hydroxide drain cleaner granules from the hardware store or I buy it online)
- 2-4 oz. essential oil of choice, optional
For the Honey and Oatmeal version, add 3 Tablespoons of honey as soon as the soap has passed the zap test (at the point when you would be adding the essential oils). Turn off the crock pot and stir in a mixture of 3 Tablespoons of oatf lour and 3 Tablespoons water. Stir well and mold as usual.
- scale (Digital is nice but not essential; check overstock stores for deals.)
- immersion/stick blender
- crock pot/slow cooker (I got mine at Goodwill on the cheap to use exclusively for soap-making.)
- large non-aluminum bowl or pitcher (Hard plastic is fine.)
- long-handled plastic spoon
- old newspaper
- soap mold (or an empty Pringles can, a washed milk carton, or special soap molds from the craft and hobby store.)
If you can’t find these secondhand, try these alternatives I selected for a balance of good reviews and low cost:
Prepare Your Ingredients:
- Weigh your oils.
- Place in cold crock pot.
- Turn heat on low and allow to melt if necessary (coconut is solid above ~70 deg.)
- Measure water and pour into pitcher or non-aluminum bowl.
- Weigh the lye.
Time to Combine
- Add lye to water and stir gently to dissolve (l like to set the bowl in the sink before I add the lye and do my pouring and mixing in the sink)
REMEMBER: Always pour the lye into the water, not the other way around or you can have a volcano. Mnemonic device–remember ‘snow falling on a lake’ is the right way. Don’t stick your head over the lye mixture during or after the add–avert your face because it can gives off fumes
- Allow the lye water to cool for a few minutes so it’s not super hot; combining the lye and water produces heat. (This isn’t the hot part of the hot process soap recipe! Even cold process soaps have this part.)
- Then pour the lye water into the oils in the crock pot and give it a gentle stir.
Grab your Blender
- Plug in your immersion blender and lower it to the bottom of the crock pot into the oil mixture. Hold the blender at a slight angle so it doesn’t suck itself to the bottom of the pot, but also make sure it is fully immersed in the solution to minimize splatter.
- Turn on the blender and gently stir.
- Keep stirring until you reach the slightly mysterious point known as “trace.” All that means is the mixture will be pudding-y enough so that stirring leaves a faint trail as you move the blender or a spoon through the mixture.
- Remove the immersion blender, unplug it, rinse it, and set it aside.
- Put the lid on the slow cooker and let it heat up on low. (This is the “hot” part of the hot process soap recipe.)
- Warm until the sides begin to pull away and it starts to look like something interesting is happening.
This will take several minutes depending on the volume of your oils and the heat of your crock pot.
- Using your spoon, stir the mixture down, scraping the bottom and sides.
- Allow to cook for an additional 20 minutes or so (times can be inexact), stirring frequently at the beginning and constantly toward the end of the cook.
Don’t leave your soap.
It will begin to start to look like applesauce and become a bit waxy-looking.
- Continue stirring until it begins to darken and become more opaque and waxy.
- Keep cooking and stirring. It may “rise” and “fall” again as it completes the saponification (turning into soap) process.
How to know when it’s done: I let a tiny dab of the soap cool on the end of my spoon and touch it with the tip of my tongue to see if the soap “zaps” like a 9-volt battery. If it doesn’t zap, it’s ready to put into the molds. If it zaps, it needs to cook some more.
Molding and Cooling
- Once it is zap-free, quickly stir in your essentials oil(s) and spoon the soap into the mold or molds. It may look quite amber at this point; it will lighten up as it cools.
- After several hours or overnight, the soap should be cool throughout and hard enough.
- Remove from the mold and slice.
Technically the soap at this point is ready to be used, but it will improve and harden with a couple of weeks curing time.
After it’s cured, package it up and keep it on hand for gift-giving and your own use. I like to print out labels I make up with the type of soap and ingredients. The sky’s the limit in terms of presentation. Simple craft paper, paper bags, cellophane treat bags, baker’s twine, sisal, ribbon or fabric make great soap adornment.
You can use any soap recipe for hot process soap, including recipes for cold process soap. However, I’d stay away from recipes that call for lots of additions like dairy or texture, especially at first. Hot process is hot and those things can increase the likelihood of scorched soap.
Here’s one of my favorite soap recipes, one I included in our book, which, incidentally, has a great section (if I say so myself) on soap-making and four of our favorite recipes for soap, as well as lots of other homemade goodies that go great in a gift basket with soap.
I hope you give it a try, you’ll love it!
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