Making Soap from Butcher Shop Trash
This is part three in a five part series on making homemade soap for personal use or sale. If you want to view the earlier posts, use these links:
Part Three: Making and Casting the Soap
In this part, I will explain how to turn your purified tallow into soap, through a process called saponification. By combining a strong alkali with some water and the tallow, you create an exothermic reaction that chemically alters the fat molecules into detergent.
I'm not going to go into the specifics of the chemistry that is going on here; it's really out-of-scope for this series. If you want to know how saponification works, check out these links:
For my soapmaking, I use a two-step process.
First, I make a base soap that has no extra fat in it, no colorings or fragrances. I make two different base soaps: lathery and not-so-lathery. The only difference is the addition of some white sugar to the lye mixture to make the base soap lathery. Since this soap does not contain extra fat (superfatting), in its raw form, it may be slightly drying or irritating to the skin. The non-lathery formula of this base soap is excellent for use as a laundry detergent, or as the base soap in homemade liquid laundry detergent.
Once this soap has finished curing, I "re-batch" or "handmill" the soap. It is at this point that I add additional fats to make the soap more moisturizing, and add colors and fragrances. During the second step is when I will place the soap into its final molding for storage or sale.
So, let's get on with making the base soap. The next part in this series will deal with the handmilling process.
Tools you'll need:
- 100% sodium hydroxide (NaOH) lye, available at some farm supply stores or online
- 1 gallon of white vinegar, to neutralize the lye in case of spill
- Rubber gloves
- Safety goggles
- Scale accurate to 0.1g for measuring lye and one accurate to 5g for oils (I use this one for oils, and this one for lye)
- Non-reactive container to weigh the lye
- Non-reactive container to mix lye
- Non-reactive tool to stir lye mixture
- pH test strips, either full range [0-14] or alkaline range [7-14], available at drug stores and aquarium stores
- Stick blender, preferably with stainless steel shaft (I melted my plastic one!)
- Heat-resistant container in which to cast the hot soap
When mixing lye with water, the mixture will heat up quite a bit! Make sure you are using a non-reactive and heat-resistant container to mix in!
During the soapmaking process, there is risk of what is called "the volcano." This soapy, bubbly mixture is extremely hot and can cause second and possibly third degree burns if you get it on your skin. Make sure you watch your soap carefully while it's cooking to avoid the volcano, and have cold water nearby in case any gets on your skin!
Preparing Your Recipe
For simplicity, I use the metric system for all my measurements. It's just plain better when you're dealing with chemicals that can maim you. Feel free to use whatever units you want, but I will use metric measurements here.
I will be using the following amounts of materials to make a base "lathery" soap:
- 1000.0 g beef tallow
- 380.0 g COLD distilled water
- 142.6 g lye
- 10 g sugar (omit this if you don't want a lathery base soap)
If you want to use different amounts to make more or less soap, DO NOT just "scale" this recipe up or down. Use the Soap Lye Calculator at soapcalc.net to get an accurate recipe. The soap calculator does not have a field for the addition of sugar to improve lathering, so you can use 10g per kilogram of base oils.
Make the SoapWeigh your ingredients. Be careful. Take your time to be precise. When working with the lye, make sure you are wearing gloves and eye protection!
Once you're at trace, cover the crockpot and put it on low. While you're waiting for it all to heat up and cook, line your temporary mold with wax paper for easy removal later. This batch took about 30 minutes to get to the next stage.
This stuff is extremely hot! Treat it like molten lava! It will burn the bejeesus out of you if you get it on your skin!
Now, test the pH. Take a small sample of your soap from the crockpot and wet it sightly with some water. Touch one of the pH strips to the wet soap and read the pH according to the package instructions. Your soap is safe if it's pH lies between 8 and 9. pH levels much higher than 9 can irritate the skin considerably. If the pH is too high, your soap is lye-heavy and either needs additional fat to react with, or it needs time to cure. If you follow this recipe precisely, you should wind up with a good soap.
Some people like to use the "zap test," but pH strips are more precise and you're not risking a chemical burn to your tongue. However, if you don't have access to pH strips, I suppose the "zap test" is better than nothing. If you do get zapped by a lye-heavy soap, I suggest swishing vinegar in your mouth to neutralize any lye that remains on your tongue to minimize any chemical burns.
Set your base soap aside to cure and harden for a few days, or until you're ready to begin making handmilled soap.
ALTERNATE ENDING: If you don't want to handmill and just want to use hot-process soap, before molding, add 30g of additioinal tallow to the mixture and stir it in completely. This will superfat the mixture and give it moisturizing properties. If you want to add colors and fragrances, allow the soap to cool to about 160F, then add your colorants and fragrance oils and stir them in completely. Then proceed with molding and cutting.
|Now, clean up your mess so your spouse doesn't kill you for tearing the kitchen up!|