I’ve been a soapmaker since the age of 12, and I own and run Coniferous Soap. Today, I’m going through the basic steps of cold process soapmaking.
There are various methods of soapmaking, but cold process soapmaking is the oldest form of making soap, going back to the age of the Babylonians in 2800 B.C. In my opinion, cold process soap is the most difficult because it is a detailed, time-consuming process. Depending on the size and complexity of the recipe, one batch of soap can take multiple months from start to finish. Soap is truly a labor of love, but the results are immensely rewarding: at the end of it all, you will be left with a beautiful and useful piece of art.
To make cold process soap, a fatty acid (oil) is mixed with an alkali (lye) in a chemical process called saponification. Some people are uncomfortable using lye because it is a caustic substance. There are a few safety precautions to follow, but contrary to common belief, there is no free-floating lye left in cold process soap.
Before you start: there is some equipment you will need. Lots of these items you probably already have in your home.
OILS: The ‘big three’ of soap-making – olive, coconut, and palm – are best for beginners because they are inexpensive and easy to work with.
LYE: Sodium hydroxide, NaOH, can be purchased online.
WATER: Lye is mixed with distilled water to create an aqueous solution that is later added to the oils. Make sure it is distilledwater- tap water can contain minerals or impurities that will affect the turnout of your soap.
SOAP MOLD: Molds come in all different sizes and materials. The most common are wood, acrylic (plastic), and silicone molds. For your first batch, you can use any small container, like a Tupperware, empty yogurt container, or small cardboard box lined with freezer paper. Just make sure there are no food remnants or dirt in your container before using it.
STICK BLENDER: This is a must have. Stick blenders cut mixing time down from several hours to a couple minutes. They can be found on Amazon and Target in the ‘kitchen’ department.
LYE-SAFE CONTAINER: Pyrex type containers, polypropylene plastic containers, or stainless steel containers are appropriate for creating the lye water solution. Do not use an aluminum container, or any aluminum utensils for that matter, because aluminum reacts with lye.
GOGGLES: Protective eyewear prevents eye injury or facial burns in the event of any accidents. Science goggles or even onion cutting goggles will suffice.
RUBBER GLOVES: Dishwashing gloves are a more eco-friendly option, but disposablenitrile or latex gloves work too.
SCALE: A kitchen or digital scale to measure ingredients.
Other useful tools:
UTENSILS: A couple stainless steel spoons and a rubber spatula are good for mixing oils, mixing lye water, and pouring soap into the mold.
LASER THERMOMETER: Easy way to keep track of your lye water and oil temperatures.
Once you have all of these you are ready to go!
Dress the part: you should wear long sleeves, long pants, gloves, goggles, and closed toe shoes for safety. I recommend tying back any long hair as well. Your soapmaking location doesn’t have to be large, but there should be no pets or small children with you.
Measure out your lye and water using the kitchen scale based on your recipe. Slowly combine the lye and water. Always pour the lye into the water, never the other way around.
To prevent inhaling any lye dust or fumes, I suggest wearing a disposable dust mask. Don’t be confused by the name ‘cold process’- the lye water can reach temperatures of 200* F.
Measure and combine all your oils. If you have any hard oils or butters, such as coconut oil or cocoa butter, put everything on the stove on low heat until it is all completely liquid.
Combine the lye water and oils. The temperature at which you combine them will vary by recipe and personal preference, but they should be around 100*F and within 10 degrees of each other. Pour the lye water into the oils down the shaft of the stick blender.
Tap the stick blender on the bottom of the container to release air bubbles, and then begin to pulse your stick blender on its lowest speed. The bell of the stick blender should be completely submerged in the oils and lye, so make sure you choose a suitable container for blending in. Stick blend until you reach trace.
Trace is the stage where the oils and lye water have emulsified, or completely mixed together. It is important to reach trace to ensure that there are no free-floating molecules of oil or lye left. You will know you’ve reached trace when it reaches a pudding-like consistency. The phrase ‘trace’ comes from a method of checking for trace- when you remove your stick blender from your mixing container you should be able to trace lines of soap across the top of the batter.
Additives, such as colorants and fragrances, go in at this stage. Always add colorants before you add fragrance oil, because some fragrances will accelerate trace or temporarily discolor your soap. Stir in any additives using a spatula or whisk.
Pour your soap into the mold. Congrats! You’ve completed your first soap. Let the soap sit in the mold for 24-48 hours before un-molding. After removing the soap from the mold, cut it into bars and let it cure for 4-6 weeks.
Curing your soap allows moisture in the bars to evaporate before use, which leaves you with a harder, longer-lasting bar. Additionally, curing provides extra time for the pH of your bar to lower to gentle, skin-safe levels.