Whether made in a large manufacturing plant or made in small batches in a kitchen, soap is made by mixing fats and/or oils with lye (sodium hydroxide). The reaction is called saponification. During saponification, the lye with some of the fats/oils is transformed into glycerin. Commercial manufacturers remove the glycerin and use it in lotions or sell it. Handcrafters allow the glycerin to remain.
What ingredients do handcrafted soap makers use?
I believe the majority use vegetable oils. I have not taken a survey, but I belong to a lot of groups and that seems to be the case. The most popular oils are coconut, palm and olive. These oils make the bar hard. Coconut Oil also does a good job of cleansing. I add Sunflower Oil and Shea Butter for conditioning and moisture.
Much study goes into which oils are used and in what proportion. Soap makers strive to get the perfect combination of cleansing, hardness, bubbly lather, creamy lather and moisturization.
Some people use lard. Lard is animal fat and a turn off for some. However, it makes a wonderful sudsy and inexpensive bar of soap. Dial Soap, Ivory Soap and the beauty bars (Caress & Dove) contain a large percentage of lard. Note that I said “beauty bars” for Dove and Caress. That is because they are not technically soap, but detergents. They are not allowed to call themselves, “soap”.
Lye (sodium hydroxide) is added to the pot. This is the stuff that requires careful handling. Lye is extremely caustic. When added to room temperature water, it will reach a boiling point in seconds. Just a small whiff hurts to breather. (When mixing lye, I go outside, stand upwind and hold my breath.) Even when cooled to room temperature, it can cause a nasty chemical burn on the skin. A splash of lye in your eye can result in blindness.
Good news is that once it is mixed with oils/fats, it changes (saponifies) and is no longer in the bar of soap. It’s just gone! Poof! And what remains is oils/fats and a new ingredient, glycerin, in a solid state.
The amount of lye needed is best determined using a saponification calculator. You can do the math yourself, but...heck, why? Not only do you need to determine how much lye to use but the amount of liquid to dissolve it.
Liquids are used as well. Water is used to mix the lye unless you buy it pre-mixed. But most soap makers, buy it in a solid form, either beads or flakes.
Another favorite liquid is goat’s milk. It gives the bar a creamy lather.
Sodium Lactate, liquid salt, is used by many soap makers in a very small about to help harden the bar. Sodium Lactate is that nasty stuff you drink to clean out your intestines before a colonoscopy. yuck!!
Fragrance and colorants are optional.
Other different and strange ingredients:
Other ingredients used span as far as your imagination.
Here’s a few somewhat common choices: yogurt, coconut milk, beer, wine, carrot juice, salts, clays, seaweed, coffee and activated bamboo charcoal. I’ve made soap with beer, seaweed, coffee and charcoal. Beer makes a very big bubbly lather and if made properly, it does not smell like beer. Josette BodyCare has facial bars made with charcoal.
Some prefer herbs for colorants: nettle leaf, turmeric, clays, beet root powder, annatto seeds, alfalfa, spinach. This list is huge. These are usually infused (allowed to soak) in an oil. I have used some of these, but I found it to be too unpredictable.
Some strange ingredients: mother’s breast milk and snake skins (soaked in the lye)
Ingredients follow trends. A current trend is to use CBD oil. However, I agree with chemist who say the properties in CBD may not withstand the extreme heat of the lye. It is most unlikely, the CBD will penetrate the surface of the skin. So using CBD oil in a wash off product is a terrible waste.
Since some oils are solid and some are liquid, they are melted to allow for mixing. The liquids including the lye is poured into the oils when all are near the same temperature. Soap makers have temperature preferences that vary between room temperature to 110⁰ F. Stainless steel equipment or hard plastics are used to avoid corrosion and melting.
Usually a stick blender is used to heat up the mix by moving the molecules in the lye causing it to interact with the oils/fats. This in turn creates trace. Trace is a thickening of the mixture which is evident when you can leave a trace of the mix on the surface by dropping some of the mix onto the top of the batch.
Here is a video clip of me making Hear Me Roar.
Cold Processed or Hot Processed
Soap is cold processed when it is poured into the mold while it is still in a pourable state. Usually soap is poured when it reaches light trace is reached. The benefit is the ability to use colors to make patterns. Experienced soap makers may pour before trace, but after emulsification to gain more time to design the soap.
Hot processed soap, is generally mixed in a crock pot on low heat with more stick blending. It will go through several stages. It will become very thick, then look like applesauce and then thicken again. Many people test it by putting a small amount on their tongue. If it zaps, like a shock from a battery, it is not ready. If it merely taste like soap, it is ready to be placed into a mold and pushed into shape.
We put it to bed
We take our prized soap and put it to bed, usually wrapping it in a towel or blanket to insulate or maintain the heat. Sometimes, cold processed soap needs a heating pad. Another method is to heat the oven to around 200⁰ F, turn the oven off and put the soap in.
And we wait…anxiously
This is the hard part.
Hot processed soaps can be unmolded and cut in 12 to 24 hours and used immediately.
Cold processed soaps need to sit in the mold for 24 – 48 hours before unmolding and cutting. These bars need to sit for several weeks before using to allow the water to evaporate, creating a hard, long lasting bar.
So now you know. Any questions, just comment below.