Soap Making in the Lab – The Art of Rescuing Mistakes
by Angelina Kotchetova
EWL R&D Lab
Errors happen when we least expect it. Our best intentions sometimes go awry. Often it’s not a huge issue. But when it’s on a larger scale, it can mean that resources go to waste. As a company, we practice LEAN Manufacturing principles, which focuses on reducing waste.
During my first days at Essential Labs, I transcribed a formula with a typo creating a very expensive– but unusable, oil blend. Instead of throwing the almost four-pound batch away, I decided to keep it for a future project. Fast forward a few weeks to a rare free afternoon. I picked up the oil I had saved and created soap using only a few other extra ingredients.
This post includes a similar soap making process and ingredients, just substitute the oils of your choice. Different oils will give you an array of hardness, cleansing, conditioning, foamy, etc. The concentration of lye should reflect your oil blend for correct saponification (the process that produces soap). Solvents like ethanol, glycerin and sugar affect the transparency of the soap.
Soap Making 101
You’ll need a few essential supplies, most of which you likely have already.
- Kitchen scale
- Mixing bowl or pot for mixing lye solution (Solution will get very hot)
- Separate pot for heating sugar water
- Double boiler
- Immersion blender
- Hot plate or stove
- Bigger pot with some forks in it
- 0.6283 lbs NaOH (lye)
- 1.3089 lbs water
- 1.3613 lbs Palm Oil
- 1.4136 lbs Coconut Oil
- 1.3613 lbs Castor Oil
- 1.5183 lbs Ethanol
- 0.7853 lbs Glycerin
- 0.9424 lbs Sugar dissolved in
- 0.6806 lbs water
Use caution while mixing harsh ingredients. Always wear Personal Protective Equipment not limited to goggles, gloves, long sleeves, and a face mask. We are using NaOH (lye) Caution: Use caustic soda and NOT a mixture like Drano.
- Wear your goggles
- Protect your hand and arms with gloves
- Use caution when mixing oil and Lye
- Be in a well-ventilated room
In a well ventilated room, add the NaOH to room temperature water. Use caution and avoid the fumes, stir and let cool.Measure the oils using a scale. Heat the oils to around 135-145⁰ F.
We recommend you prepare the lye solution (NaOH and 1.3089 lbs of water) before you measure and prepare the rest of the ingredients. The lye solution will get very hot; it needs to cool to 135-145⁰ F before mixing it with the oils.
When the lye solution cools to135-145⁰ F, gradually add it to the hot oil in a slow stream. Use an immersion blender to mix the oils and lye solution. The mixture will thicken as saponification begins. Mix until the solution “traces,” which takes about ten mins. “Trace” is a point in the soap making process when oils and the lye solution have emulsified.
Cover Soap and let sit: Gel Phase
Cover the container with a lid and let sit for about 2.5 hours scraping the pot every 30 minutes. You can speed up the saponification processes using a double boiler. This phase should take about an hour and a half. Scrape the soap solution off the side and bottom of the pot and mix it into the middle every 10-20 minutes. After the allotted time, test the pH. (Soap is above 9.5.)
Dissolve Soap in Alcohol and Glycerin
Measure and add the glycerin and alcohol to the soap solution. The alcohol will dissolve the soap. Then mix using your immersion blender for 15 minutes until all of the soap is dissolved into the solution. Keep your protective gear on, and be sure your space is well ventilated.
This step should make the solution less viscous.
Add Sugar for transparency
In a separate pan or container, heat the sugar and 0.6806 lbs of water until all sugar is dissolved. Add this sugar-water solution to the soap solution. Mix well. This step should make the solution more transparent.
After mixing, let the soap solution set for about 20 minutes and cool to about 140degrees F.
Fragrance and Dye
Creating your favorite scents is part of what makes soap-making fun. In this phase, you’ll add a personal favorite fragrance using EOs or fragrance oils. It’s also time to color your soap. Remember that citrus scents do not do well here. I used red and blue food coloring in my recipe, but pigments are great colorants, too.
Mold and Cure
I recommend using molds to set your soap. If you’re looking for a transparent soap, you’ll want to cool the soap mixture rapidly. I like to use a freezer. After the solution has hardened (dependent on size/time/temperature), you can take it out of the molds. Polish the soaps to smooth out the outer later using a cloth and alcohol. If the mold didn’t turn out as you like, you could melt the soap again to remold it. However, the soap might become less transparent each time you melt it. Place the soaps onto cardboard and in a warm, dry place to cure for two to three weeks.
Do you have a favorite soap fragrance? Any tips for novice soap makers?
Let us know how your soap turns out.