Soap is a byproduct of a reaction from oil, lye, and fat. It was first discovered, according to lore, when human sacrificial remains and ash combined in the rain and produced suds, which were discovered to clean the body quite well. While this is kind of gross, we will be doing the same thing today with oils, fats and lye.
Step 1: Step 1: Materials
We will need several different things for making hot process soap. First, we have a list of the lab equipment you will need:
1. 1 liter beaker
2. Hot Plate with stirring abilities
4. pH Strips
5. 6M Solution of Hydroxide NaOH
6. Stir Rod
7. Castor Oil
11. Lavender oil
These are all the items you will need to create you soap. I would suggest gathering them before beginning the process.
Step 2: Choosing the Oil
The oil that you use will affect everything about your soap. If you do not have the correct kinds of oil, then the soap will not have the attributes that you want. We chose two oils, castor oil and Crisco. We chose castor oils so that the soap would be more bubbly, and we chose Crisco to give it more substance.
When you choose the oil that you want to use, I would suggest the following link, LINK. This link takes you to a soap calculator that helps you to choose the oils that you want a little bit easier. It will also tell you your NaOH SAP number, which is necessary to calculate how much of each oil to use.
Step 3: Step 2: Measuring Your Oil!
You will begin by measuring out 56.7g of Castor oil. Add this to the 1 liter beaker that you got at the beginning of the instructable. Also add 170.1g of Crisco to the same beaker.
Step 4: Step 3: Heating Your Oils!
Place the 1 liter beaker on the hotplate and turn on to high until the oils are liquid. Then remove the beaker from the hotplate. Be careful, the beaker could be very hot.
Step 5: Step 4: Measure the NaOH!
This is a very important and dangerous step. The NaOH is very caustic and could seriously burn you. If you get any on your skin, immediately neutralize in the vinegar. BE CAREFUL! You will need to measure out exactly 76.5mL of NaOH. You can attain NaOH at a local hardware store or online at a soap making website.
Step 6: Step 5: Adding the NaOH
Wait until the oils have reached 120-130 degrees Fahrenheit. This is very important, as too hot of oils will destroy the reaction and too cold of oils will not complete the reaction. When it is about 125, very slowly add the NaOH, stirring the entire time with both the stirrer in the hotplate and with a metal . Once again, be very careful. DO NOT LET IT COME IN CONTACT WITH YOUR BODY! Neutralize the container that had your NaOH with vinegar before washing it in the sink and putting it away. Test it with a pH strip to be sure it is safe to handle. Continue to stir your solution. For the soapification to work, all parts must be evenly mixed. Continue until your solution becomes thick and you can make a figure eight in the solution with the stir stick.
Step 7: Some Science About Lye(NaOH)!!!
Why are we adding a chemical that can burn you to soap?? Well. That is because we need to break apart the triglycerides. This makes the glycerol molecule float away. The sodium then binds with the carboxylic end of the fatty acid to make soap!
We use a 3:1 ratio of the soap because we want the lye to affect all of the fatty acids. However, it takes three moles of lye to deal with the one mole of oil, so we use that ratio!
In addition, we do not want to use too much lye, because that will make the soap burn our hands when we wash.
Step 8: Some Science About Fat!!!
What makes different fats solid and some fats liquid at room temperature? Well that is actually controlled by their chemical makeup. Depending on the number of bends in the carbon chains, the fats will be more or less attracted to each other and will be more or less likely to stick together at room temperature. This affects us because we do not want the soap we make to be liquid, or else it will not work very well.
Step 9: Step 6: Molds, Fragrance, and Cleaning!
When the sides of the beaker start to bubble, that means that you are getting close. Turn off the heat and remove the beaker. Add 7.1g of fragrance oil now and stir in. Now pour the soap into the molds. Cover them and put them in a safe place. Now clean up everything. Be careful with hot molds and with NaOH. The longer that you leave the soap without using it, the harder it will become and the longer it will last without breaking up.