Looking for a tallow based shaving soap, I came across the following recipe and decided to try it. I made this soap yesterday, so it hasn’t cured yet and I cannot give information as to how good it is or isn’t.
33% Beef Tallow
33% Stearic Acid
20% Coconut Oil
14% Castor Oil
35% NaOH (Sodium Hydroxide)
65% KOH (Potassium Oxide)
2t Bentonite Clay per lb of oil
.5 oz. Fragrance Oil per lb of oil
I began by organizing my ingredients:
Next carefully measure out all of the ingredients:
I made an 8 ounce test batch so my ingredients are as follows:
75.9g Stearic Acid
75.9g Beef Tallow
46g Coconut Oil
32.2g Castor Oil
11.34g Sodium Hydroxide (NaOH)
29.53g Potassium Hydroxide (KOH)
87.4g Distilled Water
1 t. Bentonite Clay
.25 ounce Eucalyptus Spearmint fragrance oil
Sodium Hydroxide and Potassium Hydroxide are extremely caustic and proper protective equipment should be worn at all times while handling them. Safety Goggles and latex gloves are a must. Long sleeves and an apron are highly recommended as well.
Stearic Acid should be melted next. Because stearic acid melts at a rather high temperature, I prefer to melt it on the stove in a glass measuring cup submerged in boiling water. While this is melting, I add my tallow and Coconut oil to the crock pot and begin melting it on low. I also add about half of the castor oil.
While the oils are melting, mix the lye solution. Place distilled water in a heatproof container as the reaction will cause temperatures to rise to near boiling. Now add pre- measured Sodium Hydroxide and Potassium Hydroxide to the distilled water. NEVER add water to the lye, it is always lye to the water. This is best done in a well ventilated area as the reaction will cause fumes as well as heat. Do not breath the fumes. They will subside rather quickly. I usually mix my lye solution outside.
Now mix the remainder of the castor oil with the Bentonite clay. I use a mini mixer to blend them together smoothly. Pre-mixing will prevent the clay from clumping when you mix it in the soap at the end of the cook.
As soon as the oils in the crock pot are melted, add the lye solution, making sure to wear your protective equipment. Pour slowly so you don’t splash. Mix the lye solution and oil thoroughly . Then mix in the castor oil/bentonite clay mix. Keep cooking the mixture and stirring until you reach a light trace, then add your stearic acid to the mix. You will notice the mixture thickens up a lot now, but it is still easy to mix. 
Let it cook, it will go from a mashed potato like stage to a Vaseline like stage, being semi translucent. Now you can perform a zap test to see if the soap is fully saponified. Touch a little bit of soap to the tip of your tongue, if you feel a zap like when you touch your tongue to a nine volt battery, continue to cook. If you are not sure if it zapped, then it probably didn’t because you can clearly tell when it does. If there is no zap, you can let it cool a bit to add your fragrance oil.
You can see here it is cooled to 142 degrees. My fragrance oils flash point is 200 degrees so I can safely add the fragrance now. The picture on the right is after the fragrance is mixed in. After it is mixed in thoroughly, you can spoon the soap into your mold to harden. I used a piece of 3″ PVC pipe.
Let it stand in the mold for 24-48 hours. I unmolded mine after 24 hours, it was still a bit soft. I hope it will cure and harden significantly, time will tell.
Tip: I used a can of corn to push my molded soap out of the mold, it worked quite nicely as the can is almost the perfect diameter.
Because this soap is hot process, it is technically ready for use after it hardens. I will give mine a few days to lose some moisture before I try it, but I will come back and post some pictures when I do.
I hope you enjoy my first tutorial. Any questions or comments will be greatly appreciated.
