Let's make some soap! We all know the value of soap in our lives whether it be washing our dishes or taking a shower in the morning. Going to the store to buy some dish soap and some shampoo is easy but what about making your own personal soap in your own home? Today we will be going over just how we did it.
During this time we will be looking at the steps that we followed to make our own soap. During this process we have to take some key considerations, specifically what oils and fats you want to use, as well as any essential oils or aggregates you may want to add to your soap. Consider what characteristics you may want your soap to have and how you may want it to look and smell. Keep these things in mind as we continue to progress through the steps of soap making.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Preparations
The first thing to do when preparing to make your soap is to create a recipe for the soap. After choosing what kinds of oils and fats to use in your soap you need to calculate what's called the saponification value which tells you how much NaOH, or lye, you will need in your soap in order for it to function. In order to calculate your saponification value, we found our SAP Value in our soap calculator for NaOH. Our value was 0.183. This means that each ounce of our soap needs 0.183 ounces of lye. In order to calculate our SAP Value we followed the steps in the second image above. By following the steps seen in the second image above we calculated that we needed 150 mL of 10.3M NaOH in order to saponify our 340 grams of fats.
Step 2: Equipment and Ingredients
You will need to determine the ingredients in your soap using a soap calculator, we used www.soapcalc.net. The ingredients we used were coconut oil, olive oil, Walmart vegetable shortening, and brown sugar. The equipment that was required was a 1 Liter beaker, a hot plate, 150 mL 10.3M NaOH solution, a thermometer, and molds for your completed soap. Some precautions need to be taken account of before beginning the lab. Safety goggles should be worn at all times along with gloves because of the basic traits of sodium hydroxide which will be used throughout this lab. If sodium hydroxide should come in contact with your skin at any time a neutralization agent, such as vinegar, should be applied and then rubbed off with water until completely clean. A neutralization agent should be available at all times throughout this lab.
Step 3: Melting Fats
Melt the three fats, olive oil, coconut oil, and vegetable shortening over low heat until all solid pieces have been dissolved into a liquid. While doing this make sure to be checking the temperature frequently and make sure that the temperature stays in between 45-54 degrees Centigrade. If the temperature rises too far above this the fat will denature and will not be able to combine with the saponification agent at a later time. When fat is denatured its molecules loose there shape and are unable to bond with other materials. If this happens one should start over with new fats and try again.
Step 4: Adding Saponification Agent
Before you begin we must remind you one extremely crucial safety piece for this part of the lab.
DO NOT ADD WATER TO LYE! DOING SO WILL CREATE A DANGEROUS REACTION!
Add your lye to the solution not the other way around. This will create a dangerous reaction and could harm you. Always add your lye to the solution and not the other way around.
Once the fats are completely melted you can begin to add the amount of lie that you calculated earlier in Step 2. Slowly pour the lye into your fats and make sure that the lye is being completely stirred into the fats. Finish adding the lye to your fats and then leave the solution on low heat as you continue to stir. When the solution becomes thick you may move on to the next step. The test that we like to use to see if our soap solution is thick enough is to be able to dip the stir stick into the solution and then draw a figure eight with it.
Be careful to make sure that all of your lye is completely mixed. Any excess lye will irritate your skin and your soap will not be usable. To much fat and your soap may not become hard and will most likely not have very much cleansing power.
REMEMBER DO NOT ADD THE WATER TO LYE! DOING SO WILL CREATE A DANGEROUS REACTION!
Step 5: Adding Aggregates and Placing in Molds
When the mixture is so thick that when you lift your stirring tool out of the liquid it is possible to draw a figure 8 with the liquid your soap is ready for any essential oils or aggregates you want to add to it. Adding additional ingredients to your soap makes for a more appealing soap good for scrubbing or for leaving an appealing smell on your hands. Once essential oils and aggregates are fully combined in the soap it can be poured into the soap molds. Then the soap is left to cure for several days or even up to several weeks depending on the ingredients chosen and the desired hardness of the soap. It should take the soap about 24 hours to harden. If you want to play it safe and wait longer that is fine.
Step 6: Cleaning Up
Before you have completed your soap making process there is one final thing you should do. Clean up all the beakers, stir sticks, and any other tools you may have used during your soap making process. Make sure to use vinegar to neutralize any left over lye that is in whatever you used to poor the lye into your solution. Making sure to neutralize the lye before you pour it down the sink can save you a lot of trouble later.
Step 7: Reflections and Discussion
Our soap turned out a little softer than we would have hoped because we ran out of time in the lab and the soap did not have time to fully harden. When we tested the acidity of our soap we also found that it was moderately basic which is not good for your skin. If we were to leave the soap to cure for another week or two the consistency would be better and the pH levels would have dropped creating a better quality soap.
The selection of ingredients in our soap caused the soap to have a olive oily smell and a very moisturizing feel. The coconut oil and olive oil made a softer soap than one with only shortening which was provided for us at the lab. In comparison to other soaps ours was not as good. Other groups added essential oils and other ingredients to their soap which made for a better smelling soap. We did find that generally our soap was well rounded although not the most extravagant.
We hope that this instructable was educational and that your soap bars are super sudsy and that they do their job of keeping you clean.