How To: Make Your Own Soap

It's way better than storebought.
Publish date:
February 15, 2015
DIY, soap, weekend, How-To, Soapmaking

Making your own handmade soap sounds daunting and intimidating at first. I had no idea it was even possible before stumbling across a book on making gift baskets at my local half-priced bookstore. In the book was a bath and body basket that included handmade soap, and my brain perked up and said, “Wha?”

After that, like the obsessive person that I am, I researched soapmaking for months. How to make it, why I should make it, why it’s better than storebought, and so on. There’s a lot of resources out there for learning how to make your own soap, but here are some basics.

Handmade soap has many benefits. For one, it doesn’t contain sodium laureth sulfate, which is a foaming agent that companies add to their products in order to make them more sudsy. It’s also often what many people are reacting to when they develop allergies to beauty products. Many people who have eczema or some other skin condition swear by handmade soap for helping with their symptoms. Another reason to make and use handmade soap is that you can control the ingredients that go into it, and use as many all-natural ingredients as possible. If your goal is to eliminate synthetic chemical additives from your environment, handmade soap is the way to go.

It’s tempting to just jump right in to soapmaking, but I would encourage anyone who’s interested in it to read as much as you can and really understand the process before you start. The basic premise of soapmaking is to turn fats into soap, a process called "saponification." For this, you need a chemical agent known as sodium hydroxide, also called "lye." This is a very dangerous chemical if used improperly, so make sure you understand the science behind it before using it. Even one flake or grain of lye on bare skin can cause very serious burns. Always keep lye locked up, and definitely do not make soap if you have children or pets around. Also, you should always wear long sleeves, closed-toe shoes, long gloves, and goggles when working with lye. That stuff doesn’t mess around.

Other ingredients that you will need to make soap are fats such as oils or butters. A commonly used oil in soapmaking is coconut oil, which is a solid at 76 degrees Fahrenheit, and which melts in the soapmaking process. Other common oils are olive, canola, almond, and avocado.

Animal fats are also popular, such as lard (good old pig fat), tallow (beef fat), or elk or deer or bear. Any kind of rendered animal fat is fair game (ha, see what I did there?).

You can add other fun things to your soap after you’ve got the basic process down, such as clays or botanicals like dried lavender buds, rose petals, poppy seeds, or orange peel. Adding salt to soap makes a lovely hard bar that’s very exfoliating. The possibilities are endless, and part of the fun of soapmaking is trying out new additives and colors.

You’ll want to research different oils and fats to determine which ones you want to use in your soap. A good place to start is olive oil, coconut oil, and lard or shortening. You need to use a lye calculator to determine how much of each oil you need to use to get the best result. You can find lye calculators online or via apps. You plug in how many ounces of each oil or fat you plan to use, and the calculator will tell you exactly how much lye you should use, dispersed into how much distilled water. This needs to be done before you start your soapmaking process.

There’s a lot of different optional components to soapmaking. For example, the colors — you can make pretty colored swirls and fancy formed tops on the soap before it hardens, or you can make simple and plain soap that’s still lovely to use, if you’re just making it for your family and friends. You can buy micas and oxides that produce bright and vibrant colors for your soap, or you can use natural colorants like woad, rose madder, or paprika. Some of the fun is testing the different colors and seeing which produce the result you want.

Scent is another big part of soapmaking for many of us. If you’re just making it for your own use, you might not want to scent the soap at all. Or if you’re looking for an all-natural soap, you can use essential oils, which are distilled essences of plants. You can also buy fragrance oils — for example a duplicate of your favorite perfume to make into a soap, or you can mix and match several different fragrances into your own custom blend (my preference).

Once you have all of your ingredients that you’ll use — lye, oils, and any additives, colorants, or scents — you’ll need a mold. You can’t make this kind of soap (called "cold-processed soap") in a metal or cardboard box; lye will eat through both. You need a wooden, silicone, or plastic mold, and if the mold is wooden, it should be lined. There are many tutorials online for lining a mold with freezer paper, and it’s fairly easy to do. Almost anything can be used as a mold as long as it’s lined. There’s plenty of molds available online at a variety of vendors. I recommend trying an inexpensive one first to get the hang of the process.

What else will you need? Plastic mixing spoons and spatulas are always handy — no wooden or metal ones, as the lye will eat through them. High-density plastic mixing bowls are also helpful. I mix my lye in HDPE liter containers that I got for $1 each at the hardware store, and a HDPE bucket for mixing the batch. You don’t have to get fancy. The dollar store is a goldmine for soaping supplies.

You’ll also need a digital scale that measures in ounces, and some way to calculate the saponification values of your oils. Finally, you’ll want a stainless-steel stick blender. You can forego the blender and stir the soap by hand with a spatula, but it will take much longer to reach trace that way.

Okay, so you have your ingredients and your mold, you’re suited up in your protective gear, and you’re ready to make soap. Make sure you put down a drop cloth to protect your work surface. Measure out your oils using your handy scale, and combine them together in a container. Measure out your lye (carefully!) using the values given by your lye calculator, and mix it into the specified amount of distilled water. Stir it as it dissolves, then add it to your oils. Lye gets very hot when added to water. The heat of the lye mixture will melt your solid oils.

When everything is melted, use your stick blender for a few short bursts. Add your extra items such as fragrance, colorant, botanicals, and so on. Stick-blend again until it has reached what’s known as “trace,” or when drips from the blender dropping back onto the soap sit lightly on top instead of immediately reabsorbing.

Now you can pour your soap into the mold, which should already be lined and ready to go. Pour out the soap and decorate by swirling or texturing the top. Let the soap rest for 24 to 48 hours, then remove it from the mold. Cut it into bars, and let those bars cure for a minimum of 4 weeks; the longer the soap cures, the more mild and lovely it will be.

I am making a colored soap here, using orange and yellow micas swirled into white soap colored with titanium dioxide. The scent is a blend of rose, strawberries, waterlily, mint, and dark chocolate.

The soap is mostly finished! Now I just have to let it finish the saponification process, which typically takes 24 hours to complete. Then I will cut this batch into 12 bars and stack them on a wire rack to cure for 4 weeks. That’s cold-processed soapmaking in a nutshell. There are other ways to make soap, such as using melt-and-pour (glycerin) base, but that's a topic for another day. Enjoy making your first soap.