2.2 ounces weight Sodium Hydroxide
This mixture is much the same as those upon which we have focused all week. The process is quick, and the timing of each section is quite short. If you haven’t been following along all week, let me give you a recap of the process by which we have made this batch of soap.
Weighing time: 8 minutes
Botanicals are a simple and fun addition to soap. Most often soap makers use whole leaves, buds, twigs, or flakes. This results in the concept of scrubbing until your skin is clean, or rubbed off, or both. Soap is a pleasure product; it should clean the outside of the body as well as cleanse the spirit. If whole petals, bark, or twigs remove the top 48 million layers of your skin, they can’t bring pleasure to the process of bathing. The other thing we worry about in cold process is that great-looking botanicals don’t look so hot after their exposure to the high pH environment created by lye. Most things turn black. I find it easier to explain a few black specks as herbs than to explain why half a rose is dead inside my soap.
I have a photo showing the peppermint leaves we used. These leaves are fully dry, and I rubbed the leaves in my hand to crush and powder them more before adding to my soap. Think Thanksgiving turkey and rubbed sage for the stuffing.
We recommend grinding, rubbing, or somehow breaking the botanicals into small bits – even oatmeal. To prepare old fashioned rolled or quick cooking oats for soap making, put the oatmeal in the blender or a food processor. Grind until you get a fine flour. You will know you have the right consistency when you think it is too powdery so you considering calling us to verify it is okay.
If you forgo the grinding, someone in your household will surely declare, “Who cleaned out the lawn mower in the bath tub?!”
So, how much botanical to add? This is the question of all questions! Your test batch will prove if the amount of botanical is sufficient. If you feel like you have parsley in your belly button and basil between your toes, you have added too much plant material. However, if you use the test batch soap and say, “Self, next time you make this soap, it is okay to add more ground up plant stuff,” then you know you can add more. It is always easier to add more botanicals in the future than to cause excessive tub cleaning after each shower.
So, what about fragrances?
When adding a scenting oil, regardless of whether you are using essential oils or fragrance oils, we base the usage on the fats in the batch only. The fats never vary, but the liquid might, and it will certainly evaporate. Botanicals may vary, but the fats are a set amount each time. The Fragrance Calculator on our site gives some recommendations. Always make a test batch when using a new scent.
To calculate the amount of scent needed, go to the Fragrance Calculator. Choose Cold Process Soap from the first list. Choose the scent in the second menu, then enter the amounts of fixed oils you have used. This batch used 16 ounces of fixed oils. Now click “Calculate.”
The resulting table is pretty easy to read. We know Peppermint Essential Oil has a flash point of 163 degrees F, and a specific gravity of 0.8993. The chart gives usage percentages along the left. Across the top are methods of measurement. In our batch of soap today we are using about a 1.25% usage rate and adding 7 mL (the chart shows 6.7 mL) of Peppermint Essential Oil. This usage rate follows the SUBTLE scenting rates suggested. I can’t measure 0.7 mL in a pipette, so I rounded up to make the scenting easy to measure. Had I wanted to use teaspoons I would need 1.33, and tablespoons are 0.44, and if I wanted to weigh the Peppermint Oil it would be 0.2 ounces.
The chart gives many options. Use the measurement method that you prefer. If the fragrance will discolor, we list that information in the Fragrance Calculator. The notes on this scent say “Very minty, very clean. High rates of use can cause skin irritation.” Please use this scent mildly and continue making test batches. It is far easier to make 5 test batches before you find your favorite usage rate instead of allowing the soap to sit in the garage for 3 years so the scent can dissipate.
So, let’s recap today:
The last tip of the day. How much does one pound of fats weigh when converted to soap? Generally 16 ounces of fats makes about 20 to 22 ounces of finished soap, based on local humidity and added extras like botanicals and clay.