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 take your "melt and pour training wheels" off and start practicing 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.

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?

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...

Click here for a list of soap making supplies

Click here for a list of soap making ingredients

The Process of Cold Process Soap Making

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.

Measure out the dry lye in a small Ziploc bag so that you can safely seal it in case of interruption. Be sure to make your lye measurement exact!

Once you are ready to mix the components Remember to always pour the lye from the bag into the water, not the water into the bag of lye. The last thing you want to do is cause an explosion!

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.

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.

OK... take a deep breath and relax. You've successfully created your lye solution! Now insert one of your two cooking 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.

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.

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.

You can also add a natural preservative like grapefruit seed extract to the fats and oils mixture before moving forward.

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 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, and 110 degrees Fahrenheit for animal based soaps when I rarely make them. Experiment, once you are more experienced, but for the time being just follow the recipe.

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.

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.

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.

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. More then likely, the recipe will tell you approximately how long it will take until trace occurs. If a stick blender is used, trace can sometimes occur in as little as 2 minutes!

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.

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 plain wooden tray, 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 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.

Step 8. Once the soap has somewhat solidified within the wooden tray and is hard enough to slice, carefully measure and cut it into equal bars. Trim and carve the soap until the desired shape is formed.

Be sure to scrape off any white powder (soda ash) that formed on the top of the soap. This substance can be drying to the skin.

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

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.

Clean Up Time...

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.

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