How to make Cold Process Soap?

Cold Process soap making is a skill that requires some training. Although you can read a few blog post like this or watch a few videos and catch on there are some things you do need to be aware of, however it is pretty straight forward

How to make cold process soap? Cold process soap is made when you combine vegetable or animal based fats with an alkali then pour into a mold and let it solidify into soap.

Is it that simple?

Okay maybe it is a little bit more complicated than that but ultimately that’s exactly what it takes to make soap using the cold process soap making technique.

I know it seems weird but the process can become quite complicated when it comes to producing beautifully designed soaps. Yet to make a basic soap with basic ingredients its actually that simple… aside from the measuring that is.

Lets take a look at what it takes to make a basic cold process soap using just one oil. We will use a cheap oil and a versatile oil that can be easily found. Coconut Oil. You can learn a bit more about why we choose this oil to work with on this blog about coconut oil here at Bahamas Candle and Soap.


This recipe is for use with coconut oil and the amounts specified in this article. Using the exact measurements for lye and water with another oil will not yield the same results.

Table of contents

Tools and Supplies

  • Measuring scale
  • Mixing bowl 2 quarts
  • Heat tempered measuring cups 2-16oz 1-4oz
  • Silicone Spatula
  • Steel Whisk
  • 1tsp measure scoop
  • Soap loaf mold 42oz
  • Stick Blender
  • Disposable paper napkins
  • Soap cutter


  • 32 oz – Coconut Oil
  • 12 oz – Distilled Water
  • 5.3 oz – Lye (Sodium Hydroxide NaOH)
  • 2 oz – Fragrance or Essential Oil (optional)

Cold process soap safety preparation

When making cold process or any type of soap for that matter, safety is always a top priority at Bahamas Candle and Soap and it should be for you as well. Safety concerns come about mainly when handling lye as it is a caustic chemical and is rightly called caustic soda by many. This is not the only item you should be safety conscious about however I will discuss a few things to keep in mind BEFORE you begin making your soap.

Personal safety

You must always protect yourself when making soap. This means protecting your hands, arms, legs, feet, torso and definitely your eyes.

You will be working with super heated materials that in some instances can reach nearly 200 degrees Fahrenheit. That’s enough to cause 2nd or even third degree burns depending on which part of your body was exposed.

Use rubber gloves for your hands, if you wear glasses it is fine but if not, clear goggles are advised to protect your eyes. Wear long sleeves to protect your arms, long pants to protect your lets and closed toe shoes to protect your feet.

Mistakes do happen and if it does happen you want to make sure that you are protected. A quick story on personal safety. I once used an untested glass container to hold my lye water. If you do not know lye water when mixed can reach up to 200 degrees depending on the technique you are using. This container was fairly thick glass but it was not tempered glass. The good news was that I had the glass of lye water in a pot just in case.

In less than 2 minutes after mixing the lye with the water the heat shattered the glass. Imagine if that hot caustic substance was not contained in the pot it would have spilled everywhere and my hands, arms, lets and torso would have been burt.

This is not to scare you but to make you aware of the dangers in soap making and to always ensure you are safe. This however brings me to lye safety.

Lye Safety

Lye is an alkali that reacts with water by heating up and then bonds with oil or fat molecules to form soap in a process called saponificaiton. When your recipe is correct there should be no lye left over in your soap. This means that the lye combined with the oils and there is none left.

If your recipe is incorrect and you have too much lye which will be left over because there is no more oil to convert it can be damaging to the skin. For this reason alone we are very careful when developing our recipes by understanding the differences between various oils and how much lye is needed to convert the oils to soap.

Keep your lye in a tight container and ensure you mark the container with Danger and the words Lye/Caustic Substance.

Use gloves whenever you open the container to use the lye.

I will restate that point. ALWAYS USE GLOVES WHEN HANDLING LYE.

Ensure there are not pets or children around that may reach out and touch the substance or knock it over on your working table. The same idea stands after you combine your lye with water to make lye water. Keep it away from pets and children at all cost.

Learn more about lye safety at the Material Data Sheet (MDS) website

Cold process soaping preparation

Now that you have all your items together its time to prepare to start soaping. The preparation to soap is just as important as the safety preparation. Learning good habits in preparing before hand will help you in the long run when you are working with multiple oils and multiple colors to make layers and swirls.

Use these skills and techniques each time you get ready to make soap and you will find that it becomes easier and safer each time you soap.

Safe and secure

We covered personal and lye safety but lets get a bit deeper in preparing to soap with all your safety gear. At the time of making your soap you should atleast be wearing clothing. As you become more comfortable working with lye you may relax a bit and wear short sleaves but know that even then accidents do happen.

Ensure you are wearing a long sleeve shirt, long pants and closed toe shoes before you start to do anything.

I find it best if I start with putting on my gloves first. This way everything I do I know my hands will be safe from lye, fragrances or any other type of dye or ingredient.

Next I protect my eyes. Depending if I’m working from memory or from a recipe I will use my glasses to read or just clear goggles if making soap from memory.

Make sure there are not children around to distract you or touch anything and especially no pets especially cats that like to jump up on tables. Use a large enough work space that will be able to hold all your tools and ingredients without you reaching to far to grab an item. Now you are ready to get to work.


When it comes to making cold process soap or even hot processed soap, infact any soap including melt and pour soap. You want to keep your work station organized with everything within arms length. This means your tools near by your ingredients also nearby and your active working supplies all nearby.

To give an example here is how I organize my work area.

All my working tools are to my right as I am right handed. This includes my stick blender, whisk spatula and measuring spoon. I place the all on a napkin because as I use them in the oils or lye water they can keep the surface safe from marks or stains.

My mixing bowl is always center directly infront of my body while my lye and water are to my left. At the top above the mixing bowl is usually any additives such as colorant or fragrance. Once I have all of these things n place I am ready to work.

You can try this set up and see how it feels to you. If something feels hard to get to then adjust it so that you can have items nearby and comfortable to reach out and handle safely.

Instructions to make cold process soap

Now that you are all organized its time to make cold process soap. This will become the fun and easy part. Setting up and organizing is often the hard part as you have to ensure everything you need is at your reach.

So lets get started. Here is the order of which I make soap. Remember some things can be changed in order just find out what works best for you.

Combine Lye and Water

Lye and water which is at my left hand is combined into lye water.

Before you can make your lye water you must measure out the correct amount of lye and water. In one of your 16oz pouring glasses measure out 12 oz of distilled water. In the other measure out 5.3 oz of lye.

WARNING ALWAYS POUR YOUR LYE INTO YOUR WATER NEVER THE OTHER WAY AROUND. A good way to remember is to remember the alphabet. L comes before W so Lye into Water.

Use the whisk to stir the lye in the water until it dissolves. This combination will cause a pungent reaction if you get a whiff of the fumes. Make sure you are mixing your lye water in a well ventilated area. You will know it has dissolved when the lye water turns clear. Initially it will be a bit cloudy but as you stir, then take a break and stir again for about a minute it will begin to clear up. Let this sit and continue to clear up while you work with other ingredients.

Set you mixed lye water to the side. For me its the left side by its self. Now its time to get your oils measured.

Measure your oil

Because this cold process soap recipe only calls for one oil its pretty straight forward. Place your bowl on the scale and zero it out. Pour your coconut oil in the mixing bowl watching the scale as it fills to 32oz.

Try to keep this on point, its a good habit to learn as when it comes to multiple oils and certain techniques precision is very important to the outcome of your soap.

Depending on your location in the world or the area in which you make your soap the temperature can affect the solidity of the coconut oil. If its a bit cool the coconut oil will look cloudy. This is not a problem just put the mixing bowl in the microwave or if you are using a steel pot put it on the stove to melt the coconut oil.

Once your oil is clear it is read to be mixed with other ingredients or your lye.

Add fragrance (optional)

Adding your fragrance or essential oil directly into the oil is not a common practice for all soap making techniques. Since you are using only one oil in this batch its quite ok.

NOTE: When choosing a fragrance oil you want to find out how it behaves in cold process soap. The behavior can range from discoloration to acceleration of trace. (more on trace in the next section). Make sure you know what to expect with your fragrance oil.

Essential oils tend to behave well in cold process soaps which is to say there are no side effects to making your soap. Once you add your fragrance to the coconut oil just stir it a bit with your spatula to make sure its all blended well.

Add you lye water

Now that we have the two main ingredients set its time to combine them and make your soap batter.

Remember your lye water is still pretty hot and if you had to warm up your oils it also has some heat to it so be careful at this stage of the soap making process.

Pour the lye water (which should be clear at this time) into the oils. You can do this by a direct pour, pour it along the spatula to reduce bubbles or along the side of the mixing bowl into the oils.

Immediately you may be able to see the changes in the oil as it begins to look a bit cloudy. I like to stir the lye water in with the spatula to make sure its well mixed before I use the stick blender to take it to trace.

Stick blend to light/medium trace

Once all your lye water is in the mixing bowl along with the oils and you mixed it a bit with the spatula, its time to use the stick blender to get soaping.

Immerse the stick blender into the mixture and be sure to burp it. To burp the stick blender is to release any pockets of air trapped in the covering of the blade of the stick blender. Simply tap it at the bottom of the bowl then lean it to the side to release any bubbles. Then tap again while leaning the blender.

Begin to blend by pulsing the blade with short intervals. This will begin to mix the solution much better. After a few short burst hold the button down and get to mixing.

You will begin to see the changes in the color of the oils as it mixes with the lye. Continue to mix for a few moments followed by a string of the entire blender without the blades turning. Continue this trend until you come to a light or medium trace.

Its not time to pour your soap into the mold. Its often best to learn the various stages of trace from emulsion to light to medium to thick as each has a role in various soaping techniques.

Shape your cold process soap – Pour into mold

At a light to medium trace your soap batter should pour easily into the mold. This recipe calls for a loaf mold of 42oz however as you learn to use other shapes and other molds a light to medium trace is best to have your soap batter form to the shape of the mold.

There a variety of mold shapes and sizes on the market however for this lesson we will use the loaf mold so that we can cut your soap into traditional square bars.

Let solidify

Once your soap batter is in the mold its time to put it to bed.

Putting your soap to bed differs depending on your location mainly your temperature of the room where you will let it sit. I’ve found that in cooler rooms its best to put you soap to bed by covering it with cloth to keep the heat working within the soap batter.

In warmer areas its best to leave it uncovered but use a piece of plastic wrap or wax paper to cover the top to avoid anything falling on the top of your soap as it solidifies.

Depending on the oils you use in your soap recipe, the time it takes to harden will vary. There are hard and soft oils along with butters that can be used and the amounts of each will determine how fast your soap harden and be ready to be un-molded.

In this 100% coconut oil recipe normal within 5-8 hours the soap will become hard enough for removal. However you will not remove it at this time. Give it the full 24 hours to work as the lye will still be active in converting the oils into soap.

Cut and cure your cold process soap

Cutting your soap and letting the individual bars cure is the last and final step. To do this however after the soap was allowed to sit in the mold for 24 hours you can remove it from the mold and the silicone and prepare to cut the soap.

You will need a soap cutter or an un-sharpened knife to cut your soap. Then lastly a place for your soap bars to sit as they cure. A place away from persons touching them or playing with your soap.

Cut your cold process soap

The soap cutter is the go to cutter when it comes to cutting soap however an un-sharpened knife can do the same job. You can use a ruler to decide how thick you want your soap bars to be 1 inch is standard, and then you can make marks of where to cut your soap. You can choose to use the straight cutter or a crinkle cutter for a design.

With the loaf mold and cutting your bars into one inch you should yield 10 bars of soap. Using the cutter line up your marks and press downward being careful not to lean the cutter to the sides. A good clean straight cut is what you want.

Cure your cold process soap

Place your soap in a dry area with good ventilation. I find it best to place them on a piece of wax paper as you will be turning them during the curing process.

Cold process soap takes up to 4 weeks to cure. Curing is the process of which the soap evaporates any excess water from the bar. This makes the bar harder and last longer in the shower.

Space each bar about a fingers width apart and on its side so that air can flow between them. Each week rotate the bar to another side until it has completed the 4 weeks and standing on all 4 sides. At the end of the 4 weeks your soap is ready to be used.

NOTE: Although the soap can take up to 4 weeks to cure, know that bars made from 100% olive oil can sometimes take up to 10-12 months to cure. However in most soap recipes as soon as the lye has completed converting oils into soap the soap can be use.

Coconut oil is one of the few oils that when used in soap it can cut down on you usage time. We have tested and used 100% coconut oil in as little as 5 days after making it. This all depends on a few factors however.

Test and Use your cold process soap

Now that your soap has be cut and cured for 4 weeks its time to test the functionality of your soap. First you must make sure that all the lye has been used up in the saponification process and secondly you want an idea of how well the soap will perform.

At Bahamas Candle and Soap we have a 8 point quality check that our soaps must pass before we offer them to the public.

Zap Test for cold process soap

The zap test is a nerve racking test that is completely hands on or rather mouth on. The zap test is a simple test you can do to find out if there is any lye left over in your soap.

Its quite simple just let the bar of soap touch the tip of your tongue. That’s it. If the soap has lye in it then you will get a bit of a sting on your tongue. Nothing adverse just an off feeling much like a microscopic zap.

If you do feel a zap then that soap may not be safe to use as the lye remaining will react with the water when taking a bath and could damage the skin.

If there is not zap then your soap is good to go.

Skin Test for cold process soap

The skin test is actually the fun part. Its where you wash your hands with the soap to discover if the soap will be bubbly or creamy. Coconut soap produces good strong lather so you should expect the same with the skin test.

Next your wash your hands again but this time was from your elbows down. Again this will give you and idea of the bubbliness of the soap but also how well it cleans or conditions your skin.

Good cleaning means your skin will feel clean while conditioning means you skin will feel like you just used shampoo on it.

NOTE: A drawback to using 100% coconut oil is that is becomes extremely cleansing but also very drying. This particular recipe counters that slightly by leaving some free floating oil withing the soap to work with the glycerin to help keep your skin moisturized.

Once you are satisfied with the skin test you can fully enjoy your soap with a full body bath or shower.


Enjoy your handmade cold process soap to its fullest. Keep in mind ways to make your soap last longer while using it. Using a good soap saver helps and goes a long way.

If this is your first time using handmade soap then here is a quick tip. A little goes a long way especially for this type of bubbly soap.

Caribbean people tend to like a good lather and this soap will definitely lather well. So be moderate in application as it doesn’t take much to get a good clean bath.

Keep notes

At the end of any of your new soap recipes its a good habit to take notes from the beginning to the end. However you should also take notes on how many baths or showers you were able to take with a bar of soap.

This will give you an idea of how long one bar will last generally. Also by taking notes of what you like or what you didn’t like you can make adjustments to your recipe and make changes for the better.

Bahamas Soap Maker

Rashad has been making soaps since the inception of Bahamas Candle and Soap in 2008. Since this time he has taught a number of students how make homemade soap using the melt and pour process or the cold process of soap making. His preference is cold process soap making because of the versatility you have in designing not only the ingredients but the aesthetics of the soap. Soap making became more than a hobby for Rashad and he loves trying new techniques and teaching others how they too can make their own soap at home.

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