Hot Process Soap Tutorial (AKA the “Slow Cooker” Method)
Hi all! If you’re interested in learning to make homemade soap you will love my hot process soap tutorial. If you love to cook, you will be “cooking” like a pro here, as this approach will involve the use of a familiar kitchen tool – the slow cooker!
What could be a better way to reap the benefits of natural soap free of chemical additives?
You also will be working with a few other materials, like lye. Now I know what you may be thinking…Yikes – lye! Isn’t that dangerous?
Don’t worry, it is not as scary as it sounds as long as you take proper precautions, which I will tell you all about!
The Hot Process Explained
I think you will love the hot process method as it’s not only fun, it’s more expedient, too! True that, it is a tad more lengthy than this beginner’s approach but once you get the hang of it, you’ll wonder how you lived without it.
The hot process to soap involves taking the main ingredients (lye and water, fats and oils) and heating them , which saponifies the ingredients together quicker, but safely.
It is a little different from the cold process, in which the mixture saponifies over a period of time after being prepared and later on while setting up in molds.
Sodium Hydroxide (Lye) for Soapmaking (10 lb)
Hot Process Soap Supplies
First things first – Lye. Also known as sodium hydroxide, it needs to be labeled as 100% pure lye. (products marketed only as drain cleaner will not cut the mustard!)
Next: A slow cooker in a size at least 3 qts or more. If you already own a slow cooker, you’re in good hands. Just remember, once you start, you won’t be able to return your slow cooker back to your normal food preparation routine – proper safety and handling means you pretty much will use it exclusively for your soap making endeavors.
Now I happen to own two slow cookers, one is small (like 1.5 quart) and the other is closer to the ideal size (3-4 qt) The latter one would be a great fit and I still would have my smaller one for my normal cooking stuff. This is the one I own and I like it, only thing I wish it had was a light on the front.
A digital kitchen scale; will be important for measuring your ingredients.
A stick blender, which will make the stirring process easier on you.
Oils: Some that work well include coconut, olive, almond..pretty much the same kind you may be familiar with in cooking. As you learn more about your craft, you’ll find that you’ll enjoy experimenting with different oils.
And don’t forget the molds! You may be able to improvise with a hard nonporous container which can work too…but there are a range of good quality ones like these:
⚠️ Safety Precautions
First of all, to combine the lye and water, you need to do one other thing first….get one of those kitchen measuring scales and weigh your mixture. I suggest you get one of those two-liter sized pitchers with the top to prepare the lye and water. You may also want to consider labeling the pitcher with something like “Hazardous -contains lye” to deter the kiddos.
· Always wear rubber gloves – like the kind that reach your elbows
· Use protective eyewear such as goggles
· Avoid directly inhaling the fumes
· Mix lye/water in a plastic pitcher…metal/aluminum could cause a chemical reaction!
· Pitchers, spoons etc. should be used exclusively for soap making and never re-used for any other purpose because of possible contamination.
Start stirring that pot stat, because at this stage, it could cause an explosion-yikes(!) It will have fumes when you start the mixing process. If you can, take it outside, if not make sure your workspace is well ventilated.
Hot Process Soap Making
The lye mixture will be at a temperature of about 100 degrees F on its own. A stovetop or slow cooker will be used here. You want to melt your oils of choice in the implement first, and then add the lye and water mixture. if using a slow cooker, keep it at a low setting and time it for about 15 minutes.
Stir with spatula…the substance will start to “gel” as it is heated. This video goes into more depth.
Checking For Trace
At some point you want to check for a “trace” or trail…when you can take a spatula and pick up a little dab of the mixture and drizzle it across the top and it leaves a trail of the mixture – it is a sign that the ingredients have emulsified which is important.
Image credit – Image courtesy of SoapQueen
All right, you’re almost home free! Now set the slow cooker to low heat and let the mixture sit for up to an hour to complete cooking.
If you want to add colors and fragrances, turn off the slow cooker and let the mixture cool slightly before adding them.
Now you can begin filling your molds with the cooled mixture. After doing so put them in a safe place to cure. Hot process soap has the least lengthy cure time; usually about 24-48 hours is needed. After Day One you are free to cut it into slices, and it’s even usable, too!
However, it is usually best if you give it about a week of extra curing time to achieve its optimum level of firmness.