Cold Process Soap Making Tutorial A Lesson in Lye Soap Making

Want to know how to use the cold process soap making method to create soap completely from scratch? Are you ready to start practicing in the "real deal" in lye soap making?

Well, you've come to the right place! On this page (and throughout this site) I'm going to explain cold process soap making so that you can create beautiful, handmade soaps right in your kitchen.

Oh, and don't worry about your experience level... It really doesn't matter. The information on this site ranges from beginner to advance. So, whether you're a complete novice, or a soap making pro, stick around, have some fun, and maybe you'll learn something new about making soap at home.

Before we get started, I would like to explain the two main aspects of cold process soap making that make it my favorite style:

  1. You are always in complete control of what goes into your soap because you create it from scratch.
  2. It's an absolute blast! The cold process soap making method neatly mixes science with art to form a unique crafting experience.

Ready to make your own? Good! Now let's get started...

So, what are your first steps?

The very first thing you must do is understand what soap is. This is absolutely vital in learning cold process soap making.

Now choose a soap making recipe. You can use your own, or pick out a project from my ever growing library of soap recipes.

Next, make sure that you review these soap safety guidelines.

Finally, gather all your supplies and ingredients...

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The Process of Cold Process Soap Making

Now that you have all your ingredients and equipment prepared, you are ready to begin the actual lye soap making procedure.

At this point, make sure that you are wearing your rubber gloves and goggles. Don't take them off until you are completely done with all the cold process soap making steps!

Step 1: First, you need to prepare the lye solution by mixing the carefully weighed dry lye according to the recipe with the appropriate amount of water.

Make sure that you never use hard water for cold process soap making because the unwanted substances within the water could take part in the reaction. You can get your water tested for hardness at your local appliance store.

Tip: If you have hard water, and don't want to undergo the expense of purchasing a water softener, I urge you to buy distilled water. I personally always use distilled water in my soap recipes... I think it's just good practice.
measuring lye for cold process soap making
Measure out the dry lye in a small Ziploc bag or a container with a lid so that you can safely seal it in case of interruption. Be sure to make your lye measurement exact!

mixing lye
Once you are ready to mix the components Remember to always pour the lye into the water, not the water into the lye!

Mix the lye and water combination continuously until all the lye is dissolved. Do not break in mixing. Keep in mind that the reaction alone will cause the solution to heat to more then 200 degrees Fahrenheit; so be careful and only use a container that can easily withstand that type of heat!

How much water do you use? Well, most soap recipes will tell you, but as a general rule, use an approximate 1/3 lye to water ration - 3 ounces of water for every 1 ounce of lye.

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Understand that the H2O molecules do not actually take part in the cold process soap making reaction, but merely serve as a solvent. If only dry sodium hydroxide is used, it won't all be able to interact with all the oils or fats in the recipe. The addition of water ensures the equal spread of the sodium hydroxide throughout each and every ingredient.

Although the amount of water doesn't need to be exact for successful lye soap making, too much water can cause the soap to become soft while too little water can cause the soap to become caustic and dry.

taking temperature of lye solution for cold process soap recipe
OK... take a deep breath and relax. You've successfully created your lye solution! Now insert one of your two soap making thermometers into the liquid and Set the mixture to the side for later use. Be sure to keep it in a safe area away from children, pets, or any other passerby.

Pouring olive oil
Step 2: Prepare the acid by pouring the appropriate weights of the oils or fats into the large soap making pot. At this point, Make sure that you only insert the liquids.
Combining cold process soap making oils
Next, put the appropriate weights of your solid fats or oils into the 3 quart saucepan and melt to liquid form. Add this to the other liquid oils in the large pot.

Keep in mind that The measuring of oils and fats (and all other ingredients) must always be done by weight, never by volume. This is because the measurements need to be exact for the best soap making results.

With too little fats or oils, the soap will be caustic as there is leftover lye that couldn't take part in the reaction.

With too much fats or oils, the soap will become extremely soft as there will be extra unadulterated acids that could not react with any lye.

Most soap makers purposely add extra beneficial fats and oils to their recipe so that consumers can experience the added skin care effects of these oils in non saponified form. This is called super fatting or lye discounting. As super fatting on your own is a more advanced and delicate technique, just remember to follow the recipe to a tee when first starting out. Pretty much all recipes are already super-fatted for you so that there's no risk of extra lye in your soap.

You can also add a natural preservative (antioxidant) like rosemary oleoresin extract to the fats and oils mixture before moving forward.

taking temperature of cold process oils mixture
Now insert your second thermometer into this concoction and set the mixture to the side for future use.

At this point, you should have one container with a lye and water mixture (the base), and one container with the oils, fats and optional preservative (your acid).

Step 3. Now wait till both mixtures drop to the recommended temperature. Most soap recipes will indicate what temperature to mix the lye with the fats and oils, but remember that this part of the cold process soap making method is mostly subjective.

As for me, I like to mix my solutions at around 95 degrees Fahrenheit for castile soap or any other all vegetable oil soap. Although I don't personally make soap with animal fats like tallow and lard, I hear that it is recommended that you combine your ingredients at a higher temperature somewhere around 110 degrees Fahrenheit for these ingredients. Experiment, once you are more experienced, but for the time being just follow whichever recipe you may be using.

If you are extremely lucky, the two mixtures will hit the desired temperature at the same time, but more then likely you will have to adjust the temperatures to get them just right.

heating up cold process soap making oils
You can warm up either solution by inserting the container into hot water or cool it down by inserting the container into cold water until the temperatures are equal. I usually do this right in my kitchen sink.

mixing lye into oils

Step 4. After the desired temperatures are met, slowly pour the lye into the oils and fats mixture while stirring vigorously. Notice that I transfered my lye solution into a Pyrex measuring cup to make it easier to slowly pour the chemical into the oils. I did this after the lye cooled down substantially as not to risk breaking the glass with the hot lye/water solution.

This is the most important step in the cold process soap making procedure. You must stir the solution constantly and rather briskly in order for all the necessary molecules to interact. I find it best to stir the liquid in a figure eight pattern. For even faster results, you can use a powered stick blender.

testing for trace
How do you know when the soap mixture is ready? Well, when it starts to saponify. Test the mixture to see if the reaction is occurring by drizzling some soap from your mixing spoon onto the surface of the liquid.

If the soap stays on top of the solution for a brief period before sinking back into the rest of the solution, saponification has taken place, and the soap is ready. This stage is commonly called trace.

Keep on mixing until you reach trace... this should take 45 minutes to 1 hour for most cold process soap making recipes if stirred manually, but keep in mind that the time it takes for the formula to saponify may vary drastically. If a stick blender is used, trace can sometimes occur in as little as 2 minutes!

add soap making essential oils
Step 5. After trace is reached, add the other ingredients including essential oils or fragrances and other various nutrients. Be creative, or do as the recipe calls for. At this point, you can also add your soap making dye.

Mix the concoction until everything looks even toned.

pour cold process soap into mold
Step 6. Pour the soap into your choice of soap making molds. From PVC pipe to elegant decorative shapes, there is a large variety of molds to choose from. I personally like to pour my soap into a wooden loaf mold, and then cut it into bars after it hardens, but use your own creativity. After all, that's part of the fun!

Step 7. Cover the mold with its lid (or a piece of cardboard) and then wrap it with towels. You can never insulate your soap too generously! I use about 6 - 8 towels. You want to make sure that no heat can escape, as this is essential for the initial curing process.

Now leave the soap for about 18 - 36 hours depending on the ingredients used. Once again, the recipe should suggest how long to let the soap initially cure before cutting.

cutting cold process soap
Step 8. Once the soap has somewhat solidified within the wooden soap mold and is hard enough to slice, carefully measure and cut it into equal bars... or, if you are using my wooden soap mold with built in cutting slots, begin slicing your bars using the integrated guide. If needed, trim and carve the soap until the desired shape is formed.

If you used individual molds, remove the already formed soap bars.

cold process soap curing
Lay the new soap on a rack so that air can circulate around it. Flip them over about once every 6 - 8 days. The soap will now need to cure for 3 - 8 weeks depending on the recipe. Patience is essential for cold process soap making, but the wait is well worth the reward!

During this time, the soaps PH level will remarkably drop and your finished product will be wonderful mild and natural homemade soap.

Before you use your soap, be sure to scrape off any white powder (soda ash) that formed on the top of the bars. This substance can be drying to the skin.

Clean Up Time...

Remember to label every single tool as "use for soap making only" so that it's not mixed in with your cooking supplies. Even if you feel that your supplies are cleaned thoroughly, I wouldn't risk cooking with it!

Make sure to wash everything by hand. Don't use the dishwasher, because the leftover soapy residue can cause it to leak! This will also help avoid contaminating other kitchen utensils with the harmful lye.

Finally, be sure to store all extra supplies (especially lye) in a safe area away from children and pets.

Congratulations! You now know how to make soap at home using the cold process soap making method. Pick from one of my many soap recipes and give it a try! I hope that as you continue to learn about soap making, you will be able to use this website as your own personal resource.

Oh, and Don't forget, you can contact me anytime with your questions. I'm more then happy to help!

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