Cold Process Soap Making

Cold process soap making is one of the most common methods used for making homemade soaps today. 

It allows for a broad range of design techniques and lets the soap maker really express their creative side.

One of the really wonderful things about this soap making method is the amount of control you have with the soap base. 

For example, if you want to create a soap with a nice feathery swirl, you can pour the soap when it is at a very light trace.

Perhaps you would rather have fun mountainous peaks that look like whipped topping on your soap. In that case just wait and pour (glop) the soap when it is really thick. 

Of course, having this kind of control can lead to problems with decision making since you will have so many choices to make deciding which design idea to try. I think you should try them all! Just not your first time round or all at once!

Cold Process Soaps by Soap Making Essentials

Cold Process Soap Making Tutorial

The following cold process soap making tutorial has easy to follow, step-by-step instructions that will have you creating wonderfully, beautiful soaps in no time.

Before you make cold process soap, be sure that you're prepared and have everything you need.

A little extra time spent on planning pays off in the end.

I spent an entire month reading everything I could about how to make soap before I made my first batch, which in retrospect was perhaps a little bit excessive, but my first try at cold process soap making was a success!

Read the instructions all the way through before you start to make sure you have everything you need.

Step 1 - Getting Ready

Choose your location carefully.

Your soap making area should be free of distractions, have an element (stove or portable), be near an electrical outlet, have access to water and have a large, flat work surface.

Protect your area.

Lay down a protective layer on your work surface. I use a vinyl table cloth. It's cheap, easy to wipe clean so I can reuse it, and oils won't leak through.

Put down a rubber backed carpet if your floor needs protection. 

Soap Making Supplies and Tools

Assemble all equipment and ingredients.

Set up all your soap making supplies and ingredients so that they are within easy reach. It's awful trying to scramble around looking for something when your in the middle of making your soap.

Prepare your soap moulds.

If you are using a wooden soap mould you will need to line it with butchers paper. Here is a tutorial showing how to line a soap mould easily.

Prepare insulation area.

Once you have poured your soap, you will need a place for it to sit, undisturbed for the next 24 hours or so.

I like to lay down folded wool blankets in a warm, draft free area. Whether you need to wrap your soap or not is something that varies from location to location. 

Have an extra piece of butchers paper ready to place over the top of the soap if your soap mould does not have a lid.

You may also want a piece of Styrofoam or plywood to place on top. This helps to protects the soap from "accidents".

Step 2 - Preparing the Additives

Prepared soap mould and additives

When you're first learning how to make soap, it's best to limit yourself to just a couple of additives to begin with.

As you become more familiar with cold process soap making, you will be more confident about adding in other techniques.

Measure out any additives you are using such as colourants, botanical bits, extracts and essential oils.

If you are going to incorporate any soap bits into your main batch, now's the time to prepare the soap pieces and place them in a container.

I have often used clean, empty beer flats. They're free and allow the soap bits to spread out.

Through experimentation, I have found that it is better if the soap bits are somewhat warm.

Room temperature is fine if it is warm out. If your soap bits are cold, put them in a warm oven (lowest temperature) that has been turned off while you make the base.

This assures a better bond between the added soap bits and the new cold process soap base.

It also prevents temperature shock which can cause your soap base to go chalky and crumbly in places.

Step 3 - Weighing the Base Ingredients

All the steps in this cold process soap making tutorial are important but this step is crucial.

You must pay particular attention to weighing your ingredients accurately.

Make sure you are familiar with your weight scale before you start.

Inaccurate measurements can produce lye or oil heavy cold process soaps which you will either have to re-work or throw out.Learning how to make soap is a lot more fun if you don't have to throw it out!!

Make sure you get a good's the best investment you can make.

Preparing the lye solution

Prepare the lye solution.

Weigh your water and place it in the juice jug.

Before using sodium hydroxide, put on your safety equipment; goggles, gloves and long sleeve clothing.

Weigh the sodium hydroxide (lye) beads or flakes and pour them slowly into the water.

Be sure to stir the water as you pour the lye beads and keep stirring until the lye beads are completely dissolved.

You will notice fumes being produced while you are mixing the lye solution. It is a good idea to mix your lye in an area that has good ventilation.

Do not breath in the fumes. I try to hold my head as far away as possible while stirring until the lye is dissolved and then I leave the area for a few minutes until the fumes disburse.

SPECIAL NOTE: Always add the sodium hydroxide (lye) to the water. NOT the water to the sodium hydroxide. An unpleasant, violent reaction occurs if you do. Kind of like vinegar and baking soda is my understanding.

Melting the hard oils

Prepare the base oils.

Starting with the solid oils, weigh each and place it into the stainless steel pot.

Place the pot on the element and set the temperature to medium-low. As you continue to weigh the rest of the oils, the solid oils will melt.

Once the solid oils have melted and before putting the liquid oils into the pot, remove the pot from the element. Add the liquid oils.

Check temperatures.

The goal is to get the temperatures of both the oil mixture and the lye solution to approximately 90-95 degrees Fahrenheit or 32-35 degrees Celsius.

If needed, the lye solution can be heated/cooled in a hot/cold water bath in the sink and the oils can be heated on the element or cooled in a cold water bath.

Getting the oil mixture and lye solution to temperature can be tricky at first but it gets easier as you develop a feel for how long it takes the lye to cool.

Step 4 - Mixing the Lye and Oils

This is probably one of the most confusing steps when you're learning how to make cold process soap.

"How do I know how long to mix for?" and "What is this 'trace' that everyone is referring to?" are a couple of the common questions asked.

In answer to the first question - It can take anywhere from about 5 minutes to hours and hours. The ingredients you use will determine how long you must mix for. Most of my cold process recipes take about 5 to 10 minutes to trace using a stick blender and whisk alternately.

The second question is answered by the picture below. If you start to see stirring trails on the top of the soap base, you have reached 'trace'. This is very similar to when you make pudding. At first the pudding is very runny but as you mix, it becomes thicker and thicker.

This is what 'traced' soap looks like

Combine lye solution and oil mixture.

Slowly pour a thin stream of the lye solution into the pot of oils while using the whisk to stir the mixture.

Maintain a steady, strong stirring motion. Not so fast as to splash but fast enough to keep the mixture in constant motion. The idea is to get the oil, lye and water molecules to meet and combine to make soap.

You can use a stick blender if you have one. Give short 3 second bursts of power alternated with hand stirring. 

Do not overuse the stick blender because this can cause what is called a 'false trace'. Your soap will look like it has traced but if you hand stirred it for a while, you would find the mix loosening up again.

Make sure to stir thoroughly all areas of the pot. The mixture will turn creamy and opaque and then will begin to thicken.

Keep stirring until the mixture reaches a thin trace. Not too thick since we still have some ingredients to add yet.

Step 5 - Mixing in Additives and Pouring the Soap

Incorporating additives.

Mix in the additives, starting with the color and then any botanical bits. Next, stir in your essential oils. If you are adding in soap bits, now is the time to put them in the pot.

You will have to work quickly while mixing since some of the ingredients may speed up the saponification process causing the soap to become too thick to pour.

Pour the Soap.

As soon as the ingredients are mixed in thoroughly and the soap is showing a good trace, pour the soap into your soap moulds.

Carefully take the filled soap mould over to the location you will be insulating it for the next 24 hours.

Insulating Soap

Place the moulded soap on the wool blankets (if needed). Make sure there is enough of the blanket on either side to wrap around the soap moulds.

Top the soap with the piece of butchers paper and then the Styrofoam or plywood.

Fold the blankets up around the soap making sure it is well wrapped. 

Your soap should now be left for about 24 hours in the soap mould. You can check on the soap every couple of hours to see if the soap is gelling or not. If it has reached a full gel, you may want to open the blankets up a bit to let the extra heat escape and prevent overheating.

***NOTE***  Insulating your cold process soap may or may not be needed depending on your geographical location, the location in your home that the soap rests in during the saponification process, the recipe used, the temperature that you mix at and what type of mould you use!

A lot of factors contribute to how hot the cold process soap will get so you will need to keep an eye on your soap for the first few times until you are familiar with what works best for you.


While cleaning up, be sure to wipe all pots, bowls and utensils with paper towel first to remove as much of the oil and soap as possible. Too much cold process soap making oils will not be kind to your plumbing.

Step 6 - Cutting

My soap cutter

Once the soap has cooled to room temperature and is firm to the touch, you can un-mould it.

You can usually do this in 24 hours but some recipes that are high in liquid oils will need another 24 hours before they are firm enough to work with.

I use a soap cutter that requires me to push the soap block through a thin wire, so I prefer to wait a bit longer for the soap to firm up before cutting it.  

Step 7 - Curing.

Once you have cut the soap into bars, they need to cure for about 4 - 6 weeks in a cool, dry, dark location.

Place them in a single layer on a beer flat or tray lined with paper towel. Turn them each week so that all sides are exposed to the air.

And that's it! You now have some wonderful handmade soap that you made yourself.

As you can see, cold process soap making is fun and easy to learn but watch can be addictive!

› Cold Process Soap Making

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