Introduction: Making Soap With Chemistry
Soap, an unsung hero in our lives. Your health and even your social life (nobody likes dirty and smelly people) greatly rely upon soap. Soap has become an easily acquirable thing that we tend to forget is actually greatly complex in its creation and its process of removing unwanted contaminants from our day to day lives. So how do we make this magical substance? Today you are going to find out.
During this instructable I will be explaining the steps that I followed to make my own soap. During this process you have to specifically consider: What oils and fats do you want to use, and what essential oils and aggregates do I want to add? Considering these characteristics of your soap will be influence your final product. Keep these things in mind as we continue to progress through the steps of soap making.
Step 1: Formulating a Recipe
The first thing to do while making soap is to formulate a recipe. A great online resource for creating a recipe is soapcalc.net. After creating your recipe of what kinds of oils and fats you will use in your soap you need to calculate what's the “saponification value” which tells you how much NaOH, or lye, you will need in your soap in order for your oils and fats to be rendered to soap. In order to calculate your saponification value, you must found the SAP Value in our soap calculator for NaOH. for example my SAP value was 0.141. This means that for every ounce of soap there needs to be 0.141 ounces of lye. In order to calculate your SAP Value you must follow the steps in the second image above. By following the steps seen in the second image above you can calculate how much lye you will need. For example for my soap I needed 175 mL of 10.3M NaOH in order to saponify 500 grams of fats. The ingredients I used in my soap was coconut oil, Walmart vegetable shortening, peppermint essential oil, and mint leaves.
Once I had finalized my calculations and recipe I needed to gather the required equipment. I needed a 1 Liter beaker, a hot plate, 175 mL 10.3M NaOH solution, a thermometer, and molds for my completed soap. Some precautions were needed taken before beginning the the creation of the soap. Safety goggles and gloves are expected to be worn at all times because of the dangers of the basicness of sodium hydroxide, which will be used all throughout the creation of the soap. If sodium hydroxide should come in contact with your skin at any time you should neutralize the basic NaOH with a mild acid such as vinegar, once you have done so wash off the vinegar and NaOH with water.
Step 2: Begin Melting the Oils and Fats
Now begin with melting your chosen fats using your 1 liter beaker and a hot plate set on low heat. For me I began melting my shortening and olive oil. While I was doing so I was periodically checking my heat to make sure to not surpass 54 degrees or be below 45 degrees Centigrade. I was doing so because if the temperature rises too far above in heat the fat will denature and will not be able to combine with the saponification agent. When fat is denatured its molecules lose their form and it's then impossible for them to bond. If this happens you should restart the process.
Step 3: Adding the LYE
Before you begin I need to ensure that you understand the dangerous combination of LYE and water. If you combine water and LYE it will create a hazardous reaction. I repeat. DON’T DO IT.
Once you have your LYE correctly measured out slowly pour it into your fat and oil mixture. When you have finished adding the lye to your oil and fats mix leave the heat plate on low heat and continue to agititae the solution by stirring it. Stir for about 25-45 minutes until the soap becomes thick. A good example of the desired thickness is the thickness of apple sauce. Now be careful to make sure that all of your lye is thoroughly mixed. Any excess LYE will irritate your skin and your soap should not be used. Too much fat and your soap will lose its cleansing power and be brittle and soft.
Step 4: Adding Essential Oils and Aggregates
Once your soap is thick enough, it's time to make the mush that you have created to have a pleasant smell and appearance. Begin by adding your chosen essential oils and aggregates. Once essential oils and aggregates are fully mixed in the soap it can be poured into your chosen soap molds. Then the soap should be left to cure for about a week depending on your desired hardness of the soap.
Step 5: Cleaning Up
Once you have completed your soap making process you will need to properly clean your work station. this should include cleaning beakers, stir sticks, and any other tools you may have used during your soap making process. Specifically cleaning the beaker you used to measure the LYE you should rinse this beaker with vinegar. This ensures the LYE is neutralized before you pour it down the sink.
Step 6: Reflection
My soap in this experiment turned out a little softer than I would have hoped because I ran out of time in the lab and my soap did not have time to fully harden. When I tested the acidity of my soap it came out with a pH of 8 which is not perfectly neutral and it could have been better. If I would have had more time in the lab for the process of creating this soap it would have turned out much better and it would have hopefully worked. There are lots of things to improve upon in the recipe such as my soap mold and using mint leaves. The mint leaves over time became moldy and made the soap look revolting. I have lots to improve upon
Thank you for learning how to make soap with me!