To make soap you need to create a chemical reaction known as saponification. In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In other words … soap.
So if you think you’d like to give cold process soapmaking a try, here is how I do it.
Read through all of these instructions and assemble all of your materials before you begin. The actual process takes a while to do and it is mildly dangerous. Do it when you can set aside an hour, or so, free from distraction.
In addition to the ingredients in the recipe you will need:
A stainless steel stock pot – The bigger the better.
A good quality scale that measures in tenths of ounces and grams
A glass stirring rod or wooden tongue depressor for stirring lye into water
Glass Container with wide mouth for mixing lye solution. I have beakers for this.
Glass container for measuring sodium hydroxide (lye)
One small stainless steel wire whisk or an immersion blender. I recommend the latter.
A mold – I have the nifty wooden mold above, but molds can be made from PVC pipe or even an empty Pringles can. Be creative.
Basic Soap Recipe Ingredients
8 ounces sustainably sourced palm oil – solid fat
4 ounces coconut oil -solid fat
6 ounces olive oil
2.7 ounces of sodium hydroxide dissolved in 6 ounces of distilled water
This recipe will accommodate no more than 1 ounce of essential oil at trace, but that is a lot of essential oil. I never use that much.
You may use infused oils if you have them about. You may also experiment with other liquids such as beer or herbal infusions.
Before you Get Started
Read these instructions to the end.
Prepare your mold ahead of time. I line mine with butcher’s paper and set it on the old towel before we get started.
Empty both sides of your sink and be sure to have some ice on hand in case you need to give something a cold water bath.
Have your additives measured ahead of time and ready to add at trace.
Now put on your safety goggles and rubber gloves. Do not take them off until you have cleaned everything up. Lye and raw soap are incredibly caustic and dangerous. I usually send the children away.
Finally! You are ready to make the soap.
Put your wide mouth beaker in a plastic dishpan which you can add water to later, if necessary. Put the cold water in your wide-mouthed jar or beaker. Slowly pour the lye in–stirring until it is dissolved being careful NOT to breathe in the fumes. I like to mix mine under the hood of the stove and run the ventilation fan.
While you are waiting for that to cool down, melt your solid fats in your stainless steel pot. I use a ridiculously large pot, to catch the splattering that occurs during the mixing process. When the fats are melted add the oil.
Now comes the waiting game. You want both the lipid mixture and the lye water to be approximately 40 degrees Celsius (100 degrees Fahrenheit). For me ,this usually means giving the lye mixture a cold water bath; probably because of the surface area of my stock pot. I use a laboratory grade glass beaker. Please be careful if you are using a canning jar. Start by pouring warmish water into the largish basin around the jar and slowly add ice to bring down the temperature.
When both mixtures are around 40 degrees, you begin mixing. Slowly trickle the lye water into the lipids while stirring constantly. The old fashioned ways is to stir with a whisk or a spoon alternating between making circles and figure eights. As I don’t have hours to stir a pot, I use an immersion blender. It is a grand invention not to be trifled with. I actually have two so one is devoted entirely to non-food use like making soaps and lotions.
As you stir, you will notice the mixture becoming thicker and creamier. Trace is the term used for when the mixture is thick enough to hold up a dollop of itself, on its surface. At this point you can toss in your essential oils and other additives such as apricot seeds, ground oatmeal, fine clay, herb powders or whole herbs. Some people suggest mixing a bit of the solution into the additives and then adding that to the soap, but to me that seems a dangerous step when messing with raw soap. Sprinkle the additives evenly over the surface of the raw soap and stir it a few times. Do you still have your goggles and gloves on? You’d better!
Now pour your soap into the mold. Covering the opening with a lid or plastic plastic wrap. I like to bang my mold on the counter a couple of times to encourage the soap to settle and work out any air bubbles. Wrap the towel around your mold to keep it insulated. You don’t want it to cool too quickly. That may prevent it from getting hard enough.
After 24 hours you can put on your gloves and take the raw soap out of the mold and place it on a cooling rack or cutting board. Let it sit another 12 hours before cutting into bars. Stack the bars so as to allow air to circulate around them and let them sit for another 12 hours. Then you can layer them in a basket to cure with parchment paper between the layers. Cure for 4-6 weeks. I like to test mine with pH paper before I use them, but I am a safety girl.