We make a traditional cold process soap. With a simple recipe that makes about 4.5lbs per batch. We have made both castle style (plant based oils) and old fashioned lard soap. Personaly the lard soap makes for better lather and does not seem as slimy when using it. 
So let’s discuss recipe.
56oz lard.
4oz castor oil
17oz of water
7oz lye (sodium hydroxide)
Essential oil of your choice. Lavender is a vary common choice.
Ok so first you will need a large glass bowl or stainless steel pan, goggles, plastic spoon, Emerson blender, glass jar, mold and a thermometer I prefer the digital laser one.
Next mix your water and lye, ensure you add the lye to the water not the other way. If you pour the water into the lye it could explode. This is where you should put the goggles on. Now set the water and lye mixture aside. Caution this is vary hot.
Next mix your oils over low heat on the stove. This is why I prefer the steel pan. Melt the lard and add the castor oil. Now you need to get the oil and the lard lye mixture to the same temp. Within 15° at least. Then pour the lye mix into the pan.
At this stage grab your Emerson blender and start mixing don’t turn it on yet just mix moving it back and forth. Now turn on the blender and start mixing. Lard based soaps take a long time to trace. Trace is when the soap turnes into a consistency of vanilla pudding. At this step is where you add the essential oils. And any natural college to you choose. In the picture above I used coco powder to get the brown color.
Now it is time to mold your soap. I use a loaf style mold but you could use silicone molds or plastic soap molds. I use a wood loaf molds lined with wax paper.
Once the soap is in the mold enusre you jiggle it to get any air bubbles out of your soap. And let it set for 28-48 hours before removing it from the molds. Silicone Molds may take up to 72 hours before removal is possible. If using the loaf style, cut the soap into 1-1.5 inch bars, and place them in a cardboard box with air holes in the side. Ensure none of the bars are touching. Let them sit for 4-6 weeks to cure. And enjoy, we use these soaps for every thing shampoo,body wash, and hand soap.
If you have a hard time finding lye like I do check your local hardware store. Look for drain cleaner that is 100% lye. Don’t use any that is not 100%.