This is an overview of how to make soap. Very specific instructions can be found in the PDF document at the end of the Instructable.
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Step 1: Making the Molds
Make some molds! We used cut glass bottles so that our soap would be in the shape of a bottle. You can use anything from a small cardboard box to a gingerbread man cookie pan.
Step 2: Ingredients/Tools
- Cocoa Butter - 39.1g
- Palm Oil - 351.9g
- Crisco - 273.7g
- Olive Oil - 117.3g
- Lye - 269.1ml
- Lemongrass essential oil - 9 drops
- Coffee grounds - 150ml
- Erlenmeyer Flask - 400ml
- Water Bath - 1000ml Beaker
- Test Tube Clamp
- Hot plate
- 10.3M solution of Sodium Hydroxide (NaOH)
- Stir Rod
- pH strips
- 5 test tubes and test tube stand
Step 3: Sodium Hydroxide Lye (NaOH):
Lye is an extremely dangerous chemical that will burn your skin upon contact. It is used for both the cold and hot soap making methods. Do not let the chemical touch your skin in any way. Be sure to always have a bottle of vinegar close by so that if you do come in contact with the chemical, you are able to neutralize it immediately. Be prepared to complete this lab with rubber gloves and goggles so that there is no chance of immediate contact.
- The lye will need to be mixed with water before adding it to your fats.
- In this lab you will use 38% of the weight of your fat for your water weight.
- The appropriate amount of lye that you should use during this process depends on the saponification value of your recipe.
- The saponification value is determined with the soap calculator.
- Make sure that you are aware of the hazards associated with any oils in your recipe.
Step 4: Making a Recipe
- Choose your oils after doing some research about their soap making qualities.
- Use the website http://soapcalc.net/calc/soapcalcwp.asp to calculate your recipe.
- To use this tool,enter the amount of soap that you want to produce, the type of oils that you wish to use, and your desired percentages of each.
- This calculator will give you the SAP value of your recipe using either NaOH lye or KOH lye and the amount of each oil. For instructions on using the calculator and calculating the amount of lye, refer to the linked document.
- Our final recipe looked like this.
Cocoa butter: 39.1g
Palm Oil: 351.9g
Olive Oil: 117.3g
NaOH lye: 269.1g
Step 5: Soap Making Process
- Gather your tools.
- Set up boiler system with 1000 ml beaker on top of hot plate.
- Place a clamp over hot plate holding thermometer to measure temperature of solution.
- Measure oils by weight in grams and pour into the boiler system.
- Turn the hot plate to the highest temperature setting allowing all of the oils to liquify.
- After the oils reach liquid form and the temperature reaches 50ºC, turn the hot plate to the lowest setting. Acquire the appropriate amount to sodium hydroxide that is required for the desired recipe.
- When adding the lye, be sure to use extreme caution and avoid any contact with bare skin, always wear goggles to ensure no contact with the eyes.
- If the Sodium hydroxide comes in contact with the bare skin, neutralize it immediately with vinegar.
- Once the mixture has reached 120-130 degrees fahrenheit, you may slowly add the lye to the solution.
- Begin stirring the solution so that the oils are evenly mixed together Stir slowly with a stir stick and be sure the solution does not escape the beaker.
- Neutralize container that was used to hold sodium hydroxide with vinegar.
- Before pouring down the sink use a pH strip to ensure that it has a pH between 5 and 9.
- Saponification is now in progress.
- Stir well and the mixture will begin to thicken.
- Continue stirring periodically while keeping the temperature between 49 and 54 degrees celsius.
- After about 40 minutes, the mixture will become very thick.
- The soap is ready for molding when you can make drawings in it with your stir stick.
- Add any texturizing or scenting additives now, before pouring the soap in the molds.
- After pouring, cover your molds so that the soap doesn’t spill.
- Refrigeration is not necessary but will speed up hardening process.
Step 6: Detailed Instructions and Science Information
These PDF documents provide very specific instructions for making soap as well as information about the science behind the process.