Ever wondered how to make old fashioned lye soap – also known as cold process soap – the way your grandmother or great grandmother used to make? Well, here’s how it’s done!
DIY Cold Process Soapmaking
Soapmaking can be a lot of fun and very rewarding. However, it’s not something to just jump right into without first some research and understanding of the process. Not only are there precautions that need to be taken when making cold process soaps, but a failed batch can be a very expensive lesson.
Because of the many dangers associated with soapmaking due to the use of lye – also known as sodium hydroxide – and the plethora of information to be had, I recommend that you carefully research the process before starting out on your own. Details on where to obtain additional information will be included within this article.
Soapmaking involves a chemical process in which sodium hydroxide (lye) reacts with oils to make soap. This process is called saponification. Because this process requires the use of lye, important safety precautions must be taken. Rubber gloves and safety glasses should be worn during the soapmaking process, and vinegar, which neutralizes the lye, should be kept on hand in case of an accidental spill or burn. In addition to the necessary safety equipment needed for your journey into making cold process soap, there is other required equipment you’ll need to get started.
First and foremost you will need to acquire lye. Because without lye, there is no soap. The main components to make a true bar of soap are fat(s) – such as oils and butters – and an alkali – more commonly known as lye. You should be able to find lye in the plumbing section of your hardware store, at a local chemical supply store, or online. For those just getting started and without the need for a 50lb. bag of lye available from chemical supply stores, you can buy Roebic Heavy Duty Crystal Drain Opener in 2lb. containers at Lowe’s stores. (It contains 100% sodium hydroxide also known as caustic soda.) Alternatively, Red Devil Lye
can be purchased online. The brand doesn’t really matter, but it must be 99% or more pure sodium hydroxide. (If you are local to Roanoke, VA you can purchase 50lb. bags of sodium hydroxide beads locally in 50lb. bags from ChemSolv. Just be sure to transfer your bag of lye to a plastic container or double garbage bag lined box that you can seal after opening.)
can be purchased online. The brand doesn’t really matter, but it must be 99% or more pure sodium hydroxide. (If you are local to Roanoke, VA you can purchase 50lb. bags of sodium hydroxide beads locally in 50lb. bags from ChemSolv. Just be sure to transfer your bag of lye to a plastic container or double garbage bag lined box that you can seal after opening.)In addition to the lye, you’ll also need a large pot for mixing the soap. I recommend a large stainless steel pot. What type of pot you use is up to you, however, your pot cannot be aluminum. Lye reacts badly with aluminum so remember to never mix the two. You’ll also need an accurate scale to weigh your ingredients in either ounces or grams. You can use digital postal scale from an office supply store. Just be sure the scale is calibrated properly and can handle the amount of weight you will be using. You’ll also need a thermometer or two to measure the temps of your oils and lye solution. And, you’ll find that a stick blender- also known as an immersion blender – is your best friend in making soap. You can hand stir, but this method can take you hours over minutes and a stick blender also ensures even distribution of ingredients. And then of course there are the molds, soapmaking oils, and distilled water to be mixed with the lye.
- also known as an immersion blender – is your best friend in making soap. You can hand stir, but this method can take you hours over minutes and a stick blender also ensures even distribution of ingredients. And then of course there are the molds, soapmaking oils, and distilled water to be mixed with the lye.There are several types of molds you can use to create cold process soap. You can purchase tray molds that are basically hard plastic molds that will create numerous bars of soap at once. These molds should be marked suitable for cold process soapmaking since the soap gets very hot during the saponification process. You can also easily build a mold from wood, with a bottom and four sides. This type of mold will produce a log of soap that you would then cut into slices. When using a wooden mold, you must line it with parchment paper to aid in easy removal of the soap. (Freezer paper is not a good idea as it melts to the soap and mold.) Lining your mold is sort of like wrapping a present except that you are wrapping the inside of the box rather than the outside. It takes some practice to get it right. The parchment should then be secured with tape to the mold. Alternatively, you can line your mold with plastic film or a plastic office sized garbage bag. Just be sure to tape the material to the top of the mold for easy removal. You can learn how to make your own wooden soap molds here. (You can also make silicone soap molds.)
Next, we’re on to oils. The soapmaking oils are an important part of your soap. The types of oils you use will determine the properties that your soap will have. For example, three of the most popular soapmaking oils, especially for beginners, are olive oil, coconut oil, and palm oil. The olive oil helps create a moisturizing bar with a stable lather; coconut oil produces a hard, cleansing bar with a fluffy lather; and palm oil makes for a hard bar with a stable lather. Each of these oils has its own SAP (or saponification) value which determines how much lye should be used in the soap recipe for saponification to occur in such a way that it makes soap. Too much lye and you have an unusable bar of soap. Not enough and you could end up with a really soft soap with excess oil. A great source for learning more about the saponification process and the properties of various soapmaking fats & oils is Susan Miller Cavitch’s book The Soapmaker’s Companion. Her book also contains a great troubleshooting section and several of her own recipes. When creating your own recipes for soap, there are also a lot of additional free resources to help you with this process. Lye calculators, for example, will automatically calculate the amount of lye you need in a recipe based on the amounts and types of oils you plan to incorporate into your recipe. You can find multiple links to lye calculators by conducting a google search. Although I like to use the lye calculator at Majestic Mountain Sage. It is good practice to always double check the amount of lye in a recipe with a lye calculator if you are unsure of its source.
. Her book also contains a great troubleshooting section and several of her own recipes. When creating your own recipes for soap, there are also a lot of additional free resources to help you with this process. Lye calculators, for example, will automatically calculate the amount of lye you need in a recipe based on the amounts and types of oils you plan to incorporate into your recipe. You can find multiple links to lye calculators by conducting a google search. Although I like to use the lye calculator at Majestic Mountain Sage. It is good practice to always double check the amount of lye in a recipe with a lye calculator if you are unsure of its source.Let’s get down to business!
So, I guess by now you’re wondering just what you do with all of that lye and oil and equipment. Well, I’ll tell you. You make soap! Your best bet is to start by preparing your mold so that it is ready when your soap is ready to be poured. You’ll also need to cut out cardboard that will fit over the top of your mold. The cardboard will be used to help insulate your soap after it is made. Once these steps are complete, you would then measure out your distilled water as called for in the recipe you are using.
Measure the amount of distilled water called for in your recipe out in fluid ounces.
Pour your distilled water into a non aluminum container. (I like to use plastic pitchers.)
Next, measure out your lye. Be sure you have on all of your safety gear for this. Lye gets VERY hot, and chemical burns are never any fun. Be sure to have vinegar open and close by for any spills. For the lye, you will be weighing the amount needed with your scale. Place the container you’re using to measure the lye onto the scale, press tare to zero it out, then slowly pour the lye onto the scale until you reach the amount needed.
Then slowly pour your lye into the water, never the other way around as it could result in a not so pleasant volcano effect. Stir your lye into the water with a plastic or wooden spoon until it dissolves. Now set it aside to cool. If you’re mixing the lye inside, keep it on the stove with the exhaust fan turned on and step away. Or allow it to cool outside to avoid the nasty fumes. Be sure there are no children or animals underfoot who could get hurt.
Next we’re on to the oils! While the lye is cooling, you can weigh and melt your oils. I normally melt my oils all together in a large pot on the stove at medium heat. You can also melt the oils separately in canning jars within a water bath. First, however, you must weigh your oils on the scale. Weigh each oil individually. Set your container on the scale, hit tare so it zeros the weight, then slowly add the oils to the container until you’ve reached the weight the recipe calls for.
Repeat this process for all oils and fats in your recipe. I usually start with the solids first so I am adding the liquids to the pot last. Stir the oils until they are completely melted, then remove from heat.
Once your lye has cooled to at least 120 degrees F, though I find I like to use my lye-water solution between 95 and 100 degrees F, you can generally beginning pouring the lye-water into your oils. The temperature of the oils can vary depending on what the recipe you are using calls for, but the oils should not be hotter than the lye. (Refer to The Soapmaker’s Companion for information on why temperatures matter.) With your handy stick blender ready to go, very slowly pour the lye-water into the oils.
for information on why temperatures matter.) With your handy stick blender ready to go, very slowly pour the lye-water into the oils.
Begin stirring with the stick blender on low. As the lye and oil begins to incorporate, you can switch the blender to high. Stir well, moving the blender all over the bottom of the pot and up through the soap mixture.
You will continue to stir until you reach what is known as trace. When the soap has reached trace, it will sort of look like cream of wheat or a custard. When you pull the blender through the soap, it should leave a line following it, and if you pull some of the soap up then drop it on the surface of the soap, the soap should be able to support that drop. Should you not reach trace, within 15 minutes, you can rest for about 15 minutes, then start mixing again. Some oils used in soapmaking are slower to trace. Olive oil, for example, can take a much longer time to trace than other oils unless it is mixed with other oils whose properties promote a quick trace.
You would stir in any additives you’d like to use in your soap, such as fragrance or collodial oatmeal, once your soap has reached a light trace where it is just barely leaving a trail or supporting a drop. Mix these in well, especially any essential or fragrance oils, so you won’t have any “hot spots” in your soap. Generally fragrance oils account for 3-6% of your soap, but be sure to follow manufacturer’s recommendations if they are available. Note that some fragrances and essential oils can accelerate trace. Once your additives have been thoroughly incorporated, you’re ready to pour your soap into its mold!
Slowly pour your soap into the prepared mold. Drop the mold with the soap onto the counter several times to help remove any air bubbles.
Next, cover the mold with cardboard. You may tape the cardboard down onto the molds if you like. Follow this step by placing several towels or a blanket over your covered mold. This helps to insulate your soap so that the saponification process can properly occur. Your soap should then remained covered for 24 hours.
Once your soap has been in the mold for 24 hours, you can then remove the soap from the mold and cut into bars. I generally discount the amount of water used so that my soap can immediately be cut into bars. If once you unmold your soap, however, and find that it is really soft, then you can wait another day or two before unmolding and/or cutting your soap into bars. Once the soap has been removed from the mold, you will then need to allow your soap to cure in order to completely finish the saponification process. This generally takes a period of 2- 3 weeks. If you’re setting your soap to dry on a flat surface, be sure to set it on top of parchment or freezer paper to keep the oils from seeping out of the soap into the surface of your drying space. You can also dry your soaps on a rack. Once the soap has cured you can then package it to share with your friends and family!
If you’d like to see photos of the entire cold process soapmaking method, I’ve added an album to my fan page on facebook. You can view it here.
Still have questions?
Not everyone has a successful soapmaking experience the first go around. So if you’re still cautious after all of your research, then I recommend finding a friend who makes soap to teach you the process.
Ready, set, go!
Looking for an easy recipe to get you started? Well, here ya go.
Basic Cold Process Soap Recipe
19oz. coconut oil
19oz olive oil
10oz palm oil
16fl oz. distilled water
7oz lye
At trace:
2oz. – 4oz. fragrance oil of choice or 1oz. – 2oz. essential oil of choice
Follow your basic soapmaking instructions (above) for a great basic bar of soap with a creamy thick lather! This recipe will fit into one of my wooden loaf soap molds. (Instructions on how to make a loaf soap mold here.)
Remember, if you are ever substituting an oil for another oil in a recipe, you must recalculate the recipe to get the correct amount of lye needed since different oils & fats have different SAP values. Never make a substitution without completing this crucial step.
Recommended Supplier:
Mountain Rose Herbs
Bulk organic herbs, undiluted therapeutic quality essential oils, and bulk ingredients for soapmaking. They also carry a nice line of bottles, jars, and containers for packaging.
Bulk organic herbs, undiluted therapeutic quality essential oils, and bulk ingredients for soapmaking. They also carry a nice line of bottles, jars, and containers for packaging.
Natural Soap Making Kit
A natural soapmaking kit for beginners with all the ingredients you need to make your first batch of cold process soap including the lye. The box it comes in doubles as a mold.
A natural soapmaking kit for beginners with all the ingredients you need to make your first batch of cold process soap including the lye. The box it comes in doubles as a mold.
Soapmaking Resources & References:
Lye Calculator I
Soap recipe calculator from Summer Bee Meadow.
Soap recipe calculator from Summer Bee Meadow.
Lye Calculator II
RJ’s Soapin List Lye Calculator.
RJ’s Soapin List Lye Calculator.
Lye Calculator III
Lye Calculator from Majestic Mountain Sage.
Lye Calculator from Majestic Mountain Sage.
Lye Calculator IV
Pine Meadows lye calculator.
Pine Meadows lye calculator.
Soap Formulator
Enter the oils by percentage number (no percent mark, number only) OR number of ounces, pounds or grams of each oil you wish to use and select Create Recipe.
Enter the oils by percentage number (no percent mark, number only) OR number of ounces, pounds or grams of each oil you wish to use and select Create Recipe.
Recipe Writer and Lye Calculator
Recipe writer and lye calculator from Soap Crafters.
Recipe writer and lye calculator from Soap Crafters.
Weight Conversion & Percentage Calculator
Hate math? Now you can easily figure out what percentage of ingredients your recipe contains and easily create changes and re-formulate to suit you! Great for calculating lotions, fragrance and essential oils, etc. And now you can convert units of weight and temperatures too!
Hate math? Now you can easily figure out what percentage of ingredients your recipe contains and easily create changes and re-formulate to suit you! Great for calculating lotions, fragrance and essential oils, etc. And now you can convert units of weight and temperatures too!
Properties of Soapmaking Oils
This chart is for looking up various fats and oils to see what characteristics they give your soap.
This chart is for looking up various fats and oils to see what characteristics they give your soap.
Oil Properties for Soap Making
A chart of properties oils will have in your final bar of soap.
A chart of properties oils will have in your final bar of soap.
Non-Comodogenic Chart
This chart may help when formulating blends that are to be used on the face.
This chart may help when formulating blends that are to be used on the face.
Fragrance Calculator
In using the Fragrance Calculator, there are two ways to proceed.
In using the Fragrance Calculator, there are two ways to proceed.
The first method is to choose the type of product you are making and how much you are making. You then select which fragrance you would like to use. The Fragrance Calculator will then display a table of usage rates for you to select from.
The second method is to select the fragrance that you would want to use and then select the product you wish to fragrance. The main reason to use this second method is that it is easier to calculate fragrance usage for a family of products that use the same fragrance.
FDA Cosmetics Handbook
Regulations, Guidance, and Resources.
Regulations, Guidance, and Resources.
Determining Your Soap’s PH
The dictionary defines pH as “A measure of the acidity or alkalinity of a solution calculated as the common logarithm of the reciprocal of the hydrogen ion concentration in moles per cubic decimeter of solution and numerically equal to 7 for neutral solutions. pH increases with increasing alkalinity and decreases with increasing acidity. [potential of hydrogen.]“
The dictionary defines pH as “A measure of the acidity or alkalinity of a solution calculated as the common logarithm of the reciprocal of the hydrogen ion concentration in moles per cubic decimeter of solution and numerically equal to 7 for neutral solutions. pH increases with increasing alkalinity and decreases with increasing acidity. [potential of hydrogen.]“
Herbal Infusion
Herbal Infusion Techniques for using infusions in soapmaking.
Herbal Infusion Techniques for using infusions in soapmaking.
FDA Cosmetics Handbook
This handbook contains valuable information on FDA’s requirements and policies for safe production and accurate labeling of cosmetics. The material in it has been carefully selected for use in the production and distribution of cosmetic products.
This handbook contains valuable information on FDA’s requirements and policies for safe production and accurate labeling of cosmetics. The material in it has been carefully selected for use in the production and distribution of cosmetic products.
Saponification Table
Saponification chart for soapmaking oils.
Saponification chart for soapmaking oils.
Understanding Oxides, Micas & Ultramarines
The following article was inspired by a reader’s question concerning the differences between oxides, micas, ultramarines and colorants and when to use which one.
The following article was inspired by a reader’s question concerning the differences between oxides, micas, ultramarines and colorants and when to use which one.
Pricing a Bar of Soap
As a small business owner, you’re faced with all kinds of decisions from what brand of olive oil to use to whether to have a graphic designer design your logo. There are a whole lot of little decisions (name brand labels vs. generic, gel colorants vs. powder pigment) that, taken by themselves, are worth only pennies, or at most, a few dollars. But the cents and dollars add up quickly. This article will put some cold hard financial fact on paper and hopefully, make some of those “tiny” decisions a bit easier for you to make.
As a small business owner, you’re faced with all kinds of decisions from what brand of olive oil to use to whether to have a graphic designer design your logo. There are a whole lot of little decisions (name brand labels vs. generic, gel colorants vs. powder pigment) that, taken by themselves, are worth only pennies, or at most, a few dollars. But the cents and dollars add up quickly. This article will put some cold hard financial fact on paper and hopefully, make some of those “tiny” decisions a bit easier for you to make.
Tips on Embossing or Stamping Soaps
Your handcrafted soap becomes more unique and distinctive when stamped with your name or logo. The design for your stamp should be unique and recognizable so your customers will be reminded of you and your great products every time they see the design.
Your handcrafted soap becomes more unique and distinctive when stamped with your name or logo. The design for your stamp should be unique and recognizable so your customers will be reminded of you and your great products every time they see the design.
How to Shrink Wrap Soaps
I noticed a lot of people having trouble trying to decide if they want to shrink wrap. Along with that, there is the decision to buy or not to buy a sealer. I hope this short picture site will help in making that decision.
I noticed a lot of people having trouble trying to decide if they want to shrink wrap. Along with that, there is the decision to buy or not to buy a sealer. I hope this short picture site will help in making that decision.
How to Render Tallow
I make laundry soap from soap made from tallow. Tallow is beef fat. Before making tallow soap, you need to render, or purify the tallow.
I make laundry soap from soap made from tallow. Tallow is beef fat. Before making tallow soap, you need to render, or purify the tallow.
Rendering Lard for Soapmaking
You’re ready to make a batch of soap and the price of lard at the grocery store sends you home, screaming. Now what? Start calling your local butcher shops and ask for some lard fat (found around the kidneys of a pig). You’re going to need about 10 pounds of this fat to produce what most soap recipes will require, so be prepared to ask for that amount. If you’re lucky enough, you may even get this fine, white fat byproduct for free!
You’re ready to make a batch of soap and the price of lard at the grocery store sends you home, screaming. Now what? Start calling your local butcher shops and ask for some lard fat (found around the kidneys of a pig). You’re going to need about 10 pounds of this fat to produce what most soap recipes will require, so be prepared to ask for that amount. If you’re lucky enough, you may even get this fine, white fat byproduct for free!
Troubleshooting Cold Process Soap Problems
Today’s cold process soap makers have resolved many troubling issues involved with the process of making soaps. Through a long history of practical experience, trial and error, and troubleshooting the problems found in their soap batches, a variety of causes and their cures has been detailed. The list below highlights the major causes of cold process soapmaking problems, and what it generally takes to resolve the issue.
Today’s cold process soap makers have resolved many troubling issues involved with the process of making soaps. Through a long history of practical experience, trial and error, and troubleshooting the problems found in their soap batches, a variety of causes and their cures has been detailed. The list below highlights the major causes of cold process soapmaking problems, and what it generally takes to resolve the issue.
Soap Troubleshooting Chart
Cold Process Soaps Troubleshooting Chart.
Cold Process Soaps Troubleshooting Chart.
How to Build A Basic Wooden Soap Mold
This mold is a basic 3 lb. Mold. The beauty of this box is the fact that the parchment paper fits perfectly in the box and the next day, the soap just pulls out of the box and peels off the soap very easily. (Scroll halfway down the page for instructions.)
This mold is a basic 3 lb. Mold. The beauty of this box is the fact that the parchment paper fits perfectly in the box and the next day, the soap just pulls out of the box and peels off the soap very easily. (Scroll halfway down the page for instructions.)
How to Line a Wooden Soap Mold
This series of pictures will illustrate how we make the liner used to line the wooden soap mold, and how we make the cardboard form used to shape the liner paper.
This series of pictures will illustrate how we make the liner used to line the wooden soap mold, and how we make the cardboard form used to shape the liner paper.
Soapmaking colours/colors from herbs and spices
Herbs and spices for coloring CP (Cold Process) and HP (Hot Process) soap.
Herbs and spices for coloring CP (Cold Process) and HP (Hot Process) soap.
Plan for Making 4×15 Soapmaking Mold
If you wish to build your own mold, or have a friend build one for you, download and print the following drawing.
If you wish to build your own mold, or have a friend build one for you, download and print the following drawing.
Most Popular Herbs and Botanicals for Coloring
Herbs and botanicals used to color your soap naturally.
Herbs and botanicals used to color your soap naturally.
Most popular Herbs for Infusing
A list of popular herbs used for infusions in soap and toiletry making.
A list of popular herbs used for infusions in soap and toiletry making.
Preservative Usage Calculator
This calculator is easy as pie to use! Just enter the size of your batch, and choose the usage rate of the preservative you would like to use. You will then be given the amount of preservative to measure! See? Easy as pie.
This calculator is easy as pie to use! Just enter the size of your batch, and choose the usage rate of the preservative you would like to use. You will then be given the amount of preservative to measure! See? Easy as pie.
Ingredients recognized as safe by the FDA
Substances generally recognized as safe for use.
Substances generally recognized as safe for use.
Article and photos © Rebecca’s Soap Delicatessen
Good post and great resources! I’d just like to add that if you use distilled ice cubes (at about 50% of your water weight) you won’t have to wait for your lye water to cool.
Happy soaping!
Wow! Super informative and interesting. Thank you!
Is their something other then lye that I could use?
Where do you get lye?
Plumbing store
Thanks for this awesome recipe, can’t wait to try it. I don’t know if people are aware of the tragedy of using Palm oil or supporting the Palm Oil industry in any way. It is very destructive to our environment to support Palm Oil and I just wanted to make you all aware of it. Most people are not aware at all, and how would we be if nobody shared information.
http://www.theecologist.org/News/news_analysis/823928/palm_oil_giants_target_africa_in_land_grab_following_indonesia_deforestation_ban.html
above is only one link of many on the web about how the Palm Oil industry is destroying so much beauty on our planet.
Thanks for letting me share and thanks for sharing your information on how to be more self sustainable! It helps the planet so much…
When lining molds, freezer paper, with shiney side towards the soap, is actually ideal. Also, a heavy duty trashbag works wonders. Parchment or waxed papers, on the other hand, *will* result in a stuck on, messy mess.
Barefoot, you can purchase sustainable palm oil.
Allie, I had freezer paper stick but never parchment paper and I used it for years. Perhaps the brand of parchment paper makes a difference. I have found trash bags the easiest and quickest though!
Unknown, you cannot make soap without lye. I have suggestions of where to buy lye located within the article.
Great article but when posting pictures, you should have been wearing the safety gear.
Thank you for this blog.
Amazing post! Thanks so much for all these links. Great resources. I’m still afraid to try, though. Can you come over and walk me through it? ;=)
Amazing! I was always curious about soap making. Never looked it up though.Thanks for sharing! And that soap looks so pretty.
I have been reading everything I can find about soap. I want to make my own lye and make soap. I found out how to make lye, I have been looking for a recipe for the whole process. All from scratch. Just incase…someone needs to know how. Thanks if you can help.
I think it’s interesting you mention taking precautions but then in the photos the woman making soap is not wearing protective glasses or gloves! Really disappointing.
As urbbody said, you need to wear protective gloves and goggles when messing with lye. A lot of new soapmakers have no idea what they are dealing with. Even though it’s like baking a cake, the cake ingredients can’t hurt you. I’d recommend redoing your picture with gloves and goggles on. Otherwise, lots of good info.
Makes me appreciate those specialty soaps at craft fares even more.
Just made my first batch of soap! thanks for the help!
You are so welcome! Glad I could help!
I find it wonderful that, while you make a living of making soaps, you are still generously spreading tutorials and tips for us to make our own. Thank you so much!
Isabelle, Quebec, Can.
You’re welcome! Thanks for visiting!
Love your site! I asked someone why their grandma put ashes in their soap and got a link to your site as a response. Learning so much. Thank you for all the great details!!!!