Making Soap To Use In The Brewery

Not necessarily brew related, but for future reference. I made my second batch of hand soap that I use in the brewery. The last batch yielded 18 bars and lasted about two years. I could not find the same recipe but found one that is very close. It only uses olive oil as the fat, so it is cheap and easy.

I used the remaining amount of olive oil from the container I bought for the last batch. I weighed the olive oil and it came out to 46.15 ounces. I used the SMBCrafters soak-making calculator to find out how much sodium hydroxide and water to use. The batch size is designed to fill the soap mold I made from a Sams Club cutting board. I weighed out the ingredients with a digital kitchen scale.

The recipe:

46.15 oz Extra virgin olive oil
6.1 oz Sodium hydroxide
14.1 ounces of distilled water.

WARNING about sodium hydroxide: IT IS DANGEROUS!!! Handle with care!!!

After weighing all the ingredients, I took the water and sodium hydroxide out on the deck outside. There needs to be good ventilation when mixing the two. I wore protective eyewear and rubber gloves to work with this solution. I slowly poured the sodium hydroxide into the water while stirring with a stainless steel spoon. Once mixed very well, I took the temperature of the solution. The thermometer read 198°F! The chemical reaction makes a lot of heat! Always add the sodium hydroxide to the water, not the other way around. Now we have a lye solution.

While I let the lye solution cool, I heated the olive oil to about 128°F in a stainless steel pot. I let both solutions cool to below 120°F before mixing. The lye solution got down to about 117°F and the oil about 114°F. If they are within 10 degrees of each other, we are good to go.

I slowly poured the lye solution into the pot containing the oil, stirring constantly using a hand mixer. Once the combined, I put the hand mixer in the middle of the pot and ran it on low in short bursts. These hand mixers are not designed to run continuously and will burn out. So short bursts of a few seconds every so often is adequate, then mixing with the hand mixing like a spoon to keep mixing.

After about 10 to 15 minutes the soap solution began to trace. Trace is when you can drip the solution off the mixer and it leaves a trace, or trails, on the surface of the soap solution. Once mixed well and at trace, I poured the soap solution into the soap mold, scraping all I could get out of the pot with a spatula. I put the mold out of the way and put a sheet of cardboard on top to keep dust out. This will take about 48+ hours to set up and be ready to take out of the mold and cut into bars.

My soap making kit includes a soap mold, a digital kitchen scale, a stainless steel pot, hand mixer, a couple of mixing cups and utensils, rubber gloves and protective eyewear.

040119 9:00 AM: I decided to go ahead and slice the soap after it had been in the mold for 45 hours. It was harder to slice than I remember. Perhaps I can slice it next time after 36 hours or so.

My homemade slicer only had four wires. More than that would make it really hard to cut. Here is the slicer after finishing.

I put a 2×4 under the cardboard and wax paper so the slicer can slice all the way down to the cardboard. If I work on just a flat surface, the wires would not slice all the way through because they bend upwards a little bit.

Also, the way I have the steel wire installed, I had to use a screw driver inserted through the wire tightening eye screws to keep them from turning and loosening the wire as it sliced through the soap.