several pieces of two different kinds of cold process soap

How to Make Cold Process Soap: Soap Making for Beginners

Today I want to show you how to make cold process soap. Soap making can seem daunting to beginners and it is absolutely essential to take the necessary precautions. However, once you know the process and understands how it works, it gives you the possibility to create a custom soap containing only the ingredients you want. It is also very cost effective compared to purchasing handmade cold process soap.

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how to make cold process soap, four pieces of handmade soap

Making and Using Handmade Soap

I have been using handmade cold process soap for over ten years now. It all started when I was looking for a soap that wouldn’t leave my hands as dry every winter. I stumbled upon cold process soaps and started to experiment with different types from different makers. After a couple of years, I decided to try soap making myself. Since I am a chemist by training, the saponification process didn’t intimidate me and I made two batches of soap. However, it was only until last year when I wanted to be more self-sufficient, that I decided to make all the soap we use myself.

I discovered that for my family of four, we need about 1.5 kg / 3.3 lbs of soap per year. We use it for washing our hands and also instead of shower gel and shaving foam. Are you curious to know how soap making works? Let’s have a look.

How to Get Started

Precautions: Making Cold Process Soap requires the use of sodium hydroxide, also known as lye. Lye is a highly caustic base that can cause severe chemical burns. Therefore, it is indispensable that you familiarize yourself with the soap making process in depth before making your first batch of soap and take the necessary precautions. Always wear safety glasses, protective gloves and long clothing made from natural fibers to protect your skin. Don’t breathe in the fumes of the lye solution and only work in a well ventilated area.

As a starting point, I can highly recommend the video tutorials from Anne-Marie from Brambleberry. She has a whole series on YouTube about the basics of cold process soap making. In the videos, she discusses the topics of lye safety and ingredients, basic terms, fragrances and colorants.

In short, making cold process soap involves the conversion of an oil into soap in the presence of lye. This process is called saponification. Depending on the ratio of lye to oil, the soap can contain more or less amounts of oil that hasn’t been saponified. In soaping terms, these are called superfats. Superfats (so called esterified fatty acids) contribute to the nurturing quality of the soap. In addition, they also affect the softness of the soap. Ideally, soap is hard enough to not wash away too quickly and dry in between washes and contains enough un-saponified oils to have a nurturing effect.

How to Make Cold Process Soap: Ingredients

A basic soap consists of three ingredients:


Sodium Hydroxide (NaOH)

Water (distilled)

If you want to create a more refined soap, you can add:



Other Add-Ons (e.g. milk, honey, herbs, poppy seeds, salt)

The possibilities are nearly endless. To achieve a good consistency, it is essential to choose oils (or butters) in a well-balanced ratio. For example, it is absolutely possible to make a soap exclusively with olive oil as the oil component. However, it will take quite some time (at least several months) to harden.

soap making for beginners, four pieces of cold process soap

My Favorite Oil Combination for Making Cold Process Soap

After some experimentation, I landed on a basic recipe that I now use to make all of my soap. I wanted to avoid palm oil due to the deforestation problems (if you are interested, you can learn more about this topic at the WWF website).
I also wanted to incorporate local ingredients. Rapeseed is a crop that is cultivated a lot in Europe and is commonly available here. I also use rapeseed for making my own natural candles. If you want to learn how to make candles, you can read the blog post here.

45%       Olive Oil

25%       Coconut Oil

15%       Rapeseed Oil

15%       Shea Butter

    Essential Oil (3-4% of the total amount of oil)

              Clay (2 tbsp. for 1 kg soap, disperse 1:1 with water)

three pieces of cold process soap in flower, bee and butterfly shape


I only use essential oils. So far, I have tried rosemary, mountain pine, melissa and palmarosa.


I like to use natural clay. You can also omit the coloring step and see what kind of soap color you get, depending on the oils and butters you chose. Another possibility is making a strong tea with the water you need for the saponification. This will color your soap as well.


The amount of oil that is not being saponified in the soap making process can be individualized. Generally, I go for 6-8%.

To calculate the exact measurements, you can use the soap calculator from Bramblerry. A German equivalent can be found here.

How to Make Cold Process Soap: Materials

Safety Equipmentprotective glasses, gloves and clothing
Stick Blenderfor mixing the lye water with the oils to kick off the saponification process, the foot should be made out of plastic or stainless steel
Potstainless steel
Glass Jarsfor weighing sodium hydroxide and dissolving it in water
I use these small canning jars but any old glass jar will work.
Scalethis is the one I use
Spoonsstainless steel or plastic
Moldyou can re-use an old tetra pak – the ones that plant-based milks usually come in – or a round potato chip box.
In addition, I also use these silicon molds. You could also use a standard rectangular silicon mold like this one.
Towelto isolate the soap
four pieces of cold process soap

How to Make Cold Process Soap: Instructions

  1. Melt the solid oils/butters. Add the liquid oils. Let them cool to room temperature.
  2. Measure the (cold) water and sodium hydroxide separately. Slowly add the sodium hydroxide to the water, stir. The solution will heat up quickly. Wait a couple of minutes before adding more sodium hydroxide. If all the sodium hydroxide is dissolved, let the solution cool down to room temperature.
  3. Measure the fragrance, colorants and potential add-ons and have them ready.
  4. Pour the lye solution slowly into the oil mixture. Carefully put the stick blender in, try to avoid creating any air bubbles. Start blending.
  5. Alternate between blending and turning the stick blender off (and continue stirring by hand) in order not to overheat it. It will probably take a couple of minutes for the saponification process to start. You will notice that the solution will change in consistency. Add the fragrance, colorant and potential add-ons. Continue blending.
  6. If you see some “trace” (I recommend watching some explanatory videos to know what to look for), the soap is ready to be poured. Slowly pour the soap into the molds. Put the soap in a quiet spot and cover it with an old towel.
  7. Wait at least 24 hours before checking on the soap. I usually wait a couple of days up to a week. If you have difficulties getting the soap out of the smaller silicon molds, you can freeze them for a couple of hours. Large chunks of soaps should be cut into pieces now and stored in a dry place with good airflow.
  8. The soap will need six to eight weeks to cure and harden. During this process, it will lose water and the pH will drop. After this curation period, the soap is ready to be used.

Pin It For Later

Have you tried making cold process soap before? What are your favorite oils to use? Come share in the comments!

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I am a yarn dyeing artist, writer and educator.
I am also an avid knitter and love to create something with my hands every day.
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