Cold process soap is often the cornerstone of artisan handcrafted skin care businesses – and it’s no wonder why. The difference between a well-made natural bar of soap and the stuff you find in a box at the grocery store is enough to make a believer out of even the most devout Irish Spring user. The creamy lather, nourishing superfatted oil, and luxurious texture of handmade soap just can’t be beat.
Cold process soap making requires the use of lye, a caustic substance that is necessary to the process of saponification. In other words, lye is the magic ingredient that binds oil and water, transforming it into soap. Handling lye can be a little intimidating. It can cause a nasty burn if it gets onto your skin, but with the right safety precautions in place making soap can be as safe and simple a process as baking a cake or making a batch of fudge from scratch.
In fact, once most soapers get a batch or two under their belt making soap can become downright addictive. Advanced techniques like swirling, layering, and whipping, give soap makers an endless variety of recipes to experiment with. In time, you are likely to develop your own perfect recipe using your favorite ingredients and techniques. Like any craft, the time spent mastering the skill of soap making can be a reward in and of itself.
This tutorial will walk you through the basic steps involved in making a batch of cold process soap. If you are new to soap making, pick a simple recipe to start with. A simple soap recipe will have just a few different Oils and Butters, and only one or two additives, such as and exfoliant or a Fragrance or Essential Oil. For now, avoid recipes using alternative liquids like milk or beer, and forgo complicated techniques like swirling, whipping, and creating multi-colored soaps. The following recipes are two great examples of soaps that are suitable for a first project.
Once you have a little practice under your belt I recommend trying some other recipes and techniques. There is a wonderful world of soap making out there just waiting to be explored!
Arguably the most important thing to understand about soap making is that recipes are basically formulas – formulas that rely on very precise measurements in order to succeed. Any soap recipe should be double checked with a soap calculator before use – even recipes from print books and popular websites! It’s also essential that the ingredients in the recipe be measured with extreme care. That means they should always be weighed using scale and never by volume with cups or tablespoons.
While photographing this tutorial I used my own recipe for Coconut Almond Soap (which I’ll share here on The Natural Beauty Workshop sometime soon). These instructions can be used with most basic cold process soap recipes, but be sure to read any notes on your recipe regarding special techniques or extra steps that may be needed.
Once you get going you might find that you prefer using some other kinds of equipment for soap making, but this is what I use, and it is a good setup for a beginning soap maker.
- Wooden Soap Mold
- Wax paper
- Plastic wrap
- Precise scale
- 2 Thermometers (measuring to at least 220 degrees F)
- 1 Double Boiler for melting hard oils and butters
- 1 large Stainless Steel or Enamel Pot for mixing your soap
- 1 large container to mix the lye and water (Use a stainless steel pot or a large plastic pitcher with very thick walls)
- Heat-proof measuring beakers and/or measuring cups
- Heat-proof slicone spatulas
- Immersion Blender (also called a Stick Blender)
- 1 sturdy pair of rubber gloves
- 1 pair of safety goggles
- 1 plastic dish pan bucket
It’s a good practice to reserve the equipment used in soap making for soap making alone. This is especially important for any equipment that comes into contact with lye or raw soap. You don’t want any of the lye or raw soap residue making it into other projects. If you are working from home it can helpful to mark your soap making equipment as such and to store it in a dedicated place away from the kitchen. By the way, stainless steel equipment is arguably the best for use in soap making. Investing in quality equipment is worthwhile – not only for making great soap, but also for keeping the process safe.
Getting Ready to Make Soap
- The first thing you need to before getting started is to double-check your recipe using a soap calculator tool. Make sure you have the exact measurements all recorded accurately before getting started.
- Set up your soap making area in a place well away from anyone else in your home or business. You don’t want anyone else to come into contact with your work area until it has been completely cleaned and dismantled. It’s especially important to keep children and pets away while you soap.
- Work in a well-ventilated area. Fumes from mixing water and lye should not be inhaled.
- Wear long sleeves, closed-toe shoes, close fitting clothing, safety goggles, and rubber gloves to help protect yourself from lye and uncured soap.
- Cover any surfaces that may be splattered or spilled on during the soap making session. Lye can be unkind to tables and countertops!
- Gather all necessary ingredients and equipment before you get started. You don’t want to need to leave your work area mid-soap.
Making the Soap
Line your soap mold with wax or parchment paper. (Amy Warden of Great Cakes Soapworks shares a great video tutorial for this here.)
Measure the lye in a small plastic container reserved solely for this purpose, and set it aside. I like to keep the lye container and the measuring container inside a plastic dishpan while I measure it out. That way any flakes or powder that gets spilled can be rinsed away easily.
Measure the water, the oils, and any other ingredients or additives for your soap recipe and set them aside as well.
Add the water to the lye-mixing container. A large heavy-duty plastic pitcher or a stainless steel pot works well for this purpose. For safety reasons, never use tin or aluminum containers to mix lye and water.
Add the lye to the water (never the other way around). Mix slowly, then set the mixture aside to cool. Use a thermometer to keep an eye on the temperature.
Heat the oils in a small saucepan or double boiler. Melt any solid oils or butters, then bring the temperature of the oils to the temperature indicated in your recipe.
The goal here is to mix the lye solution and the melted oils together when they both reach the temperature (within about 10 degrees) that is indicated in your recipe. If your recipe doesn’t indicate a temperature, anywhere between 90 and 110 degrees Fahrenheit should do. If the lye solution has cooled too much by the time your oils have heated up you can reheat the solution by placing the container within a larger container of hot water. (Never heat the lye solution in the microwave or on the stovetop.)
When the temperatures are lined up, add the oils to your soap pot followed by the lye solution. Use a spatula to stir the ingredients together, then begin mixing with a stick blender if you have one available. (You can stir by hand, but it may take quite a bit longer)
Continue mixing the soap until it reaches a stage called “trace”. At trace the soap will be about as thick as a custard or pudding. The mixture will leave a trace when drizzled across its surface.
Mix in any additives, such as extra oils, fragrances, essential oils, colorants, or exfoliants at this point. It’s important to work quickly during this phase because some additives can cause the soap to harden very quickly (soapers refer to this as siezing) after being added.
Carefully transfer the soap into your lined soap mold. Gently tap the mold to make sure the soap settles into the bottom of the mold.
If the mold has a lid, you can cover the top with plastic wrap, then shut the lid. Wrap the mold in a large towel to insulate it, then move the mold out of the way.
Twenty-four hours later the soap should be un-molded and sliced into bars. Place the bars on drying racks where they should remain as they cure for at least four weeks. The soap will become milder as it cures so many soapers recommend curing your soap for six weeks to eight weeks before use.
This was our first post in our new Soap School series. During 2015 we’ll be sharing many more posts on soap making, including recipes, technique tutorials, and more. You can join in the fun by sharing your own soap making photos on social media using the hashtag #NBWSoapSchool. You can also email us your photos at firstname.lastname@example.org or share them to our Facebook or G+ pages. Let us know what you are working on and what you would like to see in future Soap School posts. Have a soap making question? We’d love to tackle it for you!