You are going to need to gather some items. You will need a stainless steel stockpot, some wooden spoons, a Pyrex measuring cup (at least one that will hold 2 cups, maybe more if you have it,) a thermometer, some bowls, towels for cleanup and have your table top cleaned off! Saponification is the chemical reaction that takes places while soap making. It’s a continuous action that occurs from the time you add the lye to the fats to the aging of the soap. It’s really not that hard when you get into it. This recipe is a basic one that you can add "scents" or keep it basic for a good overall cleaning soap, for bath, home and laundry.
First things first, safety! Wear safety glasses and wear latex gloves during this part of the process. Absolutely! Even the slightest amount of lye splashed onto your face or in your eyes can be hazardous. Into a glass Pyrex bowl, pour 5 cups of COLD water . Be sure it’s cold, once you add the lye, you’ll notice the water gets real hot. Weigh out 13 ounces of lye. (Aside-Lye can be tricky to find, I now get it at my old hardware store in town. They can get me most anything I want. Lye is now sold as drain cleaner. BE SURE it is 100% lye, no other dyes or chemicals added. Do not substitute anything else for lye, I cannot state this enough. One hundred percent lye. Keep looking if you can’t find it, it’s still sold. The actual chemical name is Sodium Hydroxide. Okay…weight out exactly 13 ounces of lye. Slowly add the lye to the water, not the other way around. You could have a huge mess on your hands (and face.) As you add the lye to the water, stir, stir, stir. Be sure you keep stirring until all the crystals are dissolved into the water. At this point, you should notice the water being very hot. This is normal, don’t worry.
Now let the lye come down in temperature to 90-95 degrees F. While this is cooling, melt your tallow that you have rendered and bring to 120-130 degree F.Once you have both the lye and fat at the correct temperature, add the lye to the fat slowly while stirring. Add all the lye and continue to stir. Now, you will probably stir for about 20-30 minutes. Try to make soap in warmer temperatures. What you are looking for is the mixture to come to a “trace” where you can draw a line across the top of the mixture. It’s at this point you can add any essential oil you might want to try and maybe some finely ground oatmeal or dried flower blossoms. Keep stirring until you notice the top is getting dull and you have a ring forming around the inside of your pot. Now your soap is ready to pour.
You can use soap molds, old plastic butter dishes, etc. (I use a regular bake pan 4" deep) just watch what color they are because they can stain your soap. Prepare your mold ahead of time as the soap will “seize” in the pan if it doesn’t get poured right away. Once you have poured the soap, I top off the mold with a large piece of cardboard and cover with a folded towel and put it in the oven with the light on. I add a tray of hot water below it on the lowest shelf and shut the door, no peeking. I take out the soap the next morning and uncover and take out of the mold, cut and stack to age. I set each piece of soap on it’s widest edge and let set undisturbed for 3-4 weeks before using. The longer soap ages, the better it gets. This sounds a little complicated but don’t let that scare you. This is a lot of fun! Good luck and feel free to ask questions! I'm sure I may have left out some things so if you spot it, point it out.
Again, BE CAREFUL. Here are 2 links. #1: Making lye from woodash http://www.wikihow.com/Make-Lye and #2: a youtube video. http://www.youtube.com/watch?v=gqe_LVp1iUY
I hope if SHTF you find this useful to help keep clean, not many People think of putting up soap as a prep.