TD and I decided to make soap to give as Christmas gifts this year. I didn't can enough this past summer to go around.
I took a soap making class through PCC a few months ago. Then, one day a few weeks ago, I abruptly decided that we should try it. I bought the supplies and today we're off and running.
The one problem with the calculations below is that some of the measurements are in fl oz, while all of the ingredients are added by weight. Total cost of all ingredients purchased: $141.33
$8.99 for 160 fl oz Canola oil = $0.056 / fl oz
$17.89 for 170 oz olive oil = $0.105 / fl oz
$6.99 for 96 oz Crisco = $0.073 / oz
From Mountainrose Herbs:
$11.00 for 16 oz Shea Butter = $0.687 / oz
$21.00 for 128 fl oz Coconut oil = $0.164 / fl oz
$23 for 128 fl oz Palm kernel oil = $0.179 / fl oz
From the True Value Hardware across the street:
$3.99 for 16 oz 100% lye drain cleaner = $0.25 / oz
From Sweetcakes soapmaking supplies:
$7.99 for 2 oz peppermint = $4.00 / oz
$12.50 for 2 oz lavender = $6.25 / oz
$6.00 for 2 oz jasmine fragrance = $3.00 / oz
$7.00 for 2 oz Tahitian vanilla = $3.50 / oz
$7.00 for 2 oz Vanilla lace = $3.50 / oz
The basic idea of soap is pretty simple. You mix melted fats and/or oils with a strong base (lye) and it chemically modifies the triglycerides into soap molecules. As the chemical reaction proceeds and the mixture cools down, it gets opaque and thick like pudding. This condition is called "trace" (you can see traces of your stir marks).
Roughly 95-100 degree F lye being poured into warm oil of same temp.
Using a stick blender to mix the lye into the fats.
After some mixing, but before trace.
I don't have a trace picture, but if you look on the surface of this poured soap, you'll see bumps because it was solid enough to partially hold its shape.
We have a 1/4 batch of Rachel's "tried and true" soap from the Miller Soap website. We scented it with 1 oz of Tahitian Vanilla fragrance oil, which smells very floral. The Sweetcakes website that I ordered the fragrance oil from says that this particular one turns dark brown, so we didn't try to color it. It's been poured into a black plastic Thai restaurant take-out box. This batch cost $6.41 to make.
The second batch we made up was a full batch of Sudsy All-Vegetable soap. I tried mixing it with a hand blender and it gets to trace lots faster than stirring by hand (which we did with the first batch. This batch is colored a horrible pink (we were trying for purple, but the dye we have doesn't seem to work well) and is scented with 1 oz Jasmine Fragrance. Overall, it kind of reminds me of hotels. Total cost: $16.44.
Third, we have a recipe that I got in a handout from the class I took. I tried to color it blue and ended up with a weird gray right after I added the dye, which slowly changed to a peach color as the mixture cooled. I give up on these dyes. It's originally from Rainbow Meadow, but I can't find the exact recipe on their website. Total cost: $21.65. I'm reproducing the recipe below for my own reference:
28 oz coconut oil
18 oz palm oil
42 oz olive oil
12.7 oz lye dissolved in 33 oz water
1 oz lavender fragrance
Let fat and lye cool to 92 deg F, then mix until at trace.
Next, I found a recipe containing Shea Butter, which costs $15.03. This one's scented with Vanilla Lace.