Basic Cold Process Soap Recipe

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I first published a version of this post on Claody. If you'd like to read the post, please click here.

 

I started using natural cleaners and bath and body supplies over five years ago. I was all in, and there was nothing I didn't want to try to make. Except for soap. The whole concept overwhelmed me. Hot process? Cold process? What about lye? There was just so much to know. But after trying nearly every soap in the store and getting dermatitis each time, I gave in and learned to make my own.


I found out that making soap was not hard. Or scary. If I can do it, I promise you can do it too. I'll share the basics with you, and you'll be making soap like a pro in no time.


Why make your own soap?


There are many reasons to try your hand at soap making. When you make your own soap, you control everything that goes into it. You can choose only the ingredients that you know are natural and safe. You can also be sure those ingredients are fair-trade, organic, sustainably sourced, or anything else that is important to you.


Once you become familiar with the process of making soap, you can create your own recipes to suit your own needs and wishes, and the possibilities are nearly endless. Making your own recipes is lots of fun, and in my experience, people love a gift of handmade soap. Your fun hobby can cover Christmas for your friends and family.


After your initial investment for the supplies and tools, you can save a lot of money by making soap in bulk. You may even have many of the supplies you’ll need lying around your house already, which could significantly cut your initial costs. Just be sure to keep a dedicated set of tools for making soap. You don’t want to cook food with the same supplies you made soap with.


If these great reasons aren’t enough to convince you to give it a chance, making soap is just good clean fun! See what I did there?

 
Supplies to make soap.
My soap making supplies.

Tools and supplies you’ll need- and why:


I know this list looks rather long, but please don’t be intimidated by it. I promise it all comes together fairly quickly. Below I’ll list the essentials needed to safely make your soap. There are many other things you can buy to make fancier soaps, but this is a great place to start.


You will need the following:


  • A large stainless-steel Dutch oven style pot: You’ll need this for heating and combining all your oils. I’ve read you shouldn’t use aluminum because of its reactivity. I use a cheap stainless-steel pot that I had lying around.


  • A non-reactive (wooden or heavy-duty plastic) spoon: This is for stirring your lye solution and mixing your oils in the pot. I have also read that you shouldn’t use wooden utensils because the lye could degrade the wood and cause it to splinter. I’ve never had this happen, but use your own judgment here.


  • Measuring spoons: I just use an old stainless-steel serving spoon to put my ingredients into the cups. However, if you plan to use colorants, essential oils, or other things that need exact measuring, you may want to have a dedicated set of nonreactive measuring utensils in your soaping kit.


  • An immersion blender:* This is also known as a stick blender, and it isn’t mandatory, but it helps so much with getting your soap to trace (we’ll talk about trace soon) faster, and it really saves your arms.


  • A soap mold:* either a premade mold or one you’ve constructed from cardboard: This is where you’ll pour your soap batter to let the magic of saponification do its thing. You can buy these online or make them from scraps at home. I recommend a simple box or loaf mold, as getting soap out of these is much easier than with a fancy mold. One with a lid is best to retain heat and keep things clean.


  • A digital scale:* This is for weighing your ingredients. Precise measuring is crucial to soap making. Not only does it ensure your recipe sets up correctly and makes, well, soap, it also keeps it safe for your skin. Your scale needs to be able to measure as small as ounces and have a tare feature. The tare feature allows you to “zero out” the weight after you’ve placed an item, in this case, your paper cup, on the scale to ensure an accurate weight.


  • Disposable cups: These are for weighing your ingredients to add to your pot. It’s much easier to measure your ingredients into cups you can throw out when you're done. The lye cup could have leftover lye residue that may burn you, and the oil cups will be greasy, which is not a fun mess to clean up. I like paper cups because they are lightweight and biodegradable. Since I don't reuse my cups, I buy cheap dollar store paper cups. Unfortunately, I was out when I made this batch of soap, so you can see in my photo that I used old cottage cheese containers.


  • Glass jar: This is for making your lye solution. You’ll need a glass container for your lye solution. Lye solutions get very hot as they react, so plastic isn’t a good idea here. I use a quart-sized mason jar.


  • Long gloves, such as traditional “cleaning gloves:” These are to protect your hands and arms from lye splatter or soap batter splash.


  • Infrared (IR) thermometer:* This is useful to check the temperature of your lye solution and oil mixture to know when it's time to combine the two. You can also use two candy thermometers, one in the oils and one in the lye, but I like my IR thermometer much better.


  • Eye protection: You may want to wear goggles to keep your eyes safe from any splatters.


  • Old towels or a blanket: Wrapping the mold in a blanket helps the soap retain heat. It can also promote what is known as “gel phase,” which can make soap appear shinier and more translucent. Gel phase isn’t essential for basic soap making, and I have some soap go through it and some that does not, but it always turns out just as good either way. The important thing is to keep the heat in so the soap saponifies properly and you’re left with a nice, hard bar.

 

Ingredients to make soap:


Making basic soap does not require many ingredients. You can even use just one type of oil if you pick the right one. No matter what oil or oils you choose, make sure you’re creating a combination that will lead to a stable, hard-but-still-lathers bar. This site has a great reference to help you learn more about different oils for soap making.


Here is a list of the ingredients we’ll be using for our basic soap:


  • Oil or oils of your choosing: The more you learn about soaping, you’ll discover that you can make soap with almost any oil. Which one or ones you choose is totally up to you. How much you will need will depend on the recipe you've chosen to use. After we’ve covered the basics, I’ll share the simple soap recipe that I made while writing and taking pictures for this post. I’ll also explain the recipe and calculation page in detail. You can create your own recipes at The Sage or look for some online.


  • Lye: You can't make soap without lye. I like to use Red Crown* brand. For bar soap, make sure you get sodium hydroxide. Potassium hydroxide will create liquid soap. Again, the exact amount of lye needed differs from one recipe to another, but ALWAYS use a lye calculator like The Sage to ensure your soap will be safe to use.


  • Water or other liquid for dissolving lye: Other liquids that you can use include herbal tea or milk. I rarely use plain water. I prefer to brew a strong herbal tea that complements the herbs I am using but feel free to choose whatever liquid you prefer. Just make sure you enter your chosen liquid into that field on the calculator and use the amount your calculated recipe specifies.


These ingredients are the only crucial elements to make soap, but there are many other things you can add according to your preferences. You can add dried herbs, oats, coffee grounds, colorant powders, essential oils for fragrance, cosmetic clays, honey or beeswax, etc. These things are usually added at trace. I don't often use them, so I recommend researching anything specific you want to use to see how much is needed.

 

Steps to make soap:


Before you begin making your soap, make sure to gather all your materials in the place where you’ll be working. The process tends to move along quickly, and it will go much smoother if everything you need is in one spot and ready to go. Also, make sure you are wearing your gloves and eye protection.


Always measure your liquid in fluid ounces, but your lye and oils in weight. Note: remember to use the tare function on the scale as you switch ingredients, so you know your measurements are precise.


A lye solution that has a temperature of 195.8 degrees Fahrenheit.
See how hot lye solutions can get!

First, make your lye solution. This gets hot, so you want to make sure it’s got time to cool back down. To do this, carefully measure the lye per your recipe into the cup on your scale. Measure the liquid per your recipe into the glass jar. Carefully pour the lye into the liquid. NEVER ADD WATER TO LYE! This could cause a violent eruption that could seriously injure you. Always add the lye to the liquid. Stir it gently and set it aside in a safe place. Note: Please remember this gets hot! Be very careful.


Next, measure all the other ingredients (except any extras you want to use) one at a time per your recipe and add them to your Dutch oven. Once all oils and/0r butters that you are using are in the pot, heat them on low heat on the stovetop until they all are melted and warm.


Soap oils in a pot.
All my oils, ready to become soap!

Remove the pot from the heat and allow the oil mixture and the lye solution both to cool to around 100-125 degrees F. You can place a candy thermometer in each solution, or you can use the infrared thermometer to easily scan the temperature of both without having to touch them. Once both are within that range, you’re ready to move on.


You can see in my pictures below that both the lye solution and the oils were at 119.3 degrees F. That has never happened before and probably never will again. As long as each solution is between 100 and 125 degrees F, you're good to go.


Slowly pour the lye solution into the oil mixture and gently stir to incorporate. Using the immersion blender (being very careful to keep it submerged so you don’t splatter and burn yourself), mix your soap batter until it reaches trace. You will know it has reached trace when you can use the head of the blender to “trace” a design into the batter and it stays for a few seconds without disappearing. It will look similar to a cake batter.


The three images below show the soap at various points of mixing, but before it has reached trace. It's almost there in the photo on the far right.


A soap at trace.
We have trace!

Once your soap reaches trace, it is time to add any extras such as dried herbs, oats, colorants or oils, etc. Since I will not be doing that, I won’t go into too much detail. Again, iff you plan to use these, I recommend doing some research on how much of them to add. Notice how the heart I "traced" in the batter stays for a few seconds. This is a sign your batter is ready.


If you’re not adding extras, it’s time to pour your soap into its mold. I have a wooden and silicone mold with a lid, but when I first started soaping, I used one I made with cardboard. You can do a Google search for DIY soap molds to get some ideas. You’ll want to pour the soap batter into the mold and cover it quickly to keep as much heat in as possible. You can see the parchment paper in my photo under the lid. I cover the soap batter with parchment paper before placing the lid to keep the lid from sticking to the soap as it hardens. I did learn this the hard way, and it was such a pain to get that lid off!


Wrap your mold in a couple of towels or a blanket to help it retain heat, and set it aside where it won’t be disturbed and is away from children or pets.


After a few hours, you can unwrap the mold and check on the soap. It should be thickening and beginning to look like soap. Sometimes you may see a “shinier” looking section. This is likely gel phase and is a result of the heat and not a problem. Leave your soap in the mold, undisturbed, until it has cured and is dry enough to unmold.


This may take a day or two, or even a few weeks. Be patient, your soap will unmold, some just take a little more time. You'll know it's ready to unmold when the sides of the mold separate from the soap easily and you can peel the mold off without damaging the new soap.


Once you have unmolded the soap, cut it into bars of your desired thickness and size, and set the bars on end to dry. If you have a cookie cooling rack that you can dedicate to soap, this would work best to promote airflow and even drying of the bars. If not, it's not a problem. Just remember to rotate your soap bars every few days so all the ends can dry completely.


Keep up with the date you made the soap, as it will usually take around six weeks to fully cure. Again, be patient. Using it too soon could result in a soap that is still too harsh for your skin and may be uncomfortable. It could also result in a softer bar that doesn’t last as long. Once it’s cured, store it in a dry and cool place. I keep mine in a cardboard box with a lid in a spare cabinet.


The two pictures below show my soap right after I cut it (left) and on the drying rack to cure (right).

When it's time to clean up, I just keep my gloves on and wash everything in hot water with my usual dish soap. I let it dry completely then put it back in its box to store until the next time I made soap.


The recipe and calculation sheet explained:


A soap recipe.
My recipe sheet.

You can see in my recipe that I used olive oil (which I had previously infused with calendula), sweet almond oil, castor oil, coconut oil, sunflower oil, and meadowfoam oil. I chose these oils for their skin healing, bar hardening, and lathering properties.


The website I linked to above will share more details about the properties of each oil. You will notice that the recipe shows how much I will use in ounces and the percentage of the recipe that amounts to. This is important, and you should make sure you know the maximum percentage of each oil you should use to ensure your recipe is successful.


In the section for liquids, the page shows that I listed calendula herbal tea as my liquid. In this field on the site, you would add water, milk, or whatever liquid you chose. There is also that warning again about not adding water to lye, but the lye to the water.

They also provide a lye recommendation chart. Please look carefully at this on your own calculation page. Choose an amount in the five to eight percent range. This will ensure your soap is safe to use. You’ll also see the "steps for making soap" section, which provides a quick rundown of how to produce your bubbly creation.


At the very bottom is an estimated final product yield. I honestly have never weighed my finished soap to see how accurate this is because I only use it for personal family use. However, I think this could be quite important if you planned to sell your soap.

 

Ta-da! You made soap. DIdn't I promise it wouldn't be so bad? As you start to gain confidence in your new skill, branch out, and try your own recipes. As long as you run your recipe through The Sage (or another lye calculator), you won’t mess up! There are some great books for recipes as well, and many online sources.


I have made some fancier soaps, but I really like my plain old boring calendula infused basic soap. It soothes my (very) sensitive skin and has no strong odors. I hope you find as much joy in making soap as I do!


Have you made soap, or will you give it a try? Do you have any recipes you can share with us? I'd love to read them!


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