Soap Longevity
I noticed recently that the lye calculator I have been using has a graph that shows you where your soap recipe stands as far as recommended values. I prefer this visual representation, by the way, to the table from most other calculators. What I noticed, actually, was a column called “Longevity” and most of my recipes were barely touching the recommended range. So I decided to do some research (aka googling) and found quite a few interesting threads about what contributes to how long a soap bar lasts. Here are two links with more information
There are a lot of opinions and information on these numbers based on each soap maker’s experience and knowledge. But, in a nutshell, this is what I understood:
- That some oils are more water soluble than others because of their fatty acid properties.
- Namely, that stearic acid and palmitic acid are less water soluble. So they help with soap bar hardness and longevity.
- While Lauric and Myristic fatty acids are very water soluble and they provide bubbles and cleansing values.
This link gives examples of which oils are high on the above fatty acids. Here is an abbreviated list of the most common oil for above four categories of fatty acids, but there are more types.
Stearic: Shea butter, mango butter, kokum butter, hydrogenated soybean oil
Palmitic: Palm oil, tallow, lard, cocoa butter
Lauric: Coconut oil
Myristic: Coconut oil and some exotic oils
So, my challenge, given that I do not use palm oil, is to keep the stearic acid and palmitic acid numbers high enough for a lasting bar (I aim for a number between 27 and 35 following the advice on the forum thread). I learned that shea butter and cocoa butter can help, as well as tallow. And I do not like to measure a bunch of oils for one batch, so I played with the numbers until I got something I am happy with, using five types of oils only. I only wanted to use four, actually, but I decided to include lard for some whiteness, since I am also using pomace oil.
The first time I made a unicorn theme soap, I attempted to form a unicorn shape inside the soap. Well, that did not go too well. So this time I tried putting them outside, as embeds. I am much happier with the result, though I can still improve on the cloud shaping. To go directly to the videos, scroll all the way down for the links.
LESSONS LEARNED WITH THIS BATCH
1. Achieving thick trace without acceleration with floral fragrance
I used the stick blender until just emulsified, then added fragrance and distributed with a whisk, and then stick blended again to distribute the colors. By the time I poured it was mild trace, by the time I poured the white layer it was at heavy trace, very thick. Which is good as I wanted to add the soap dough unicorns on top and do the shape of the clouds on first layer. This is what helped achieve that thickness:
- Part of it was probably because of floral fragrance
- and part of it because of the olive pomace oil
- Also, I used warmer temperatures. Soaping temperatures were in the 125’s
2. Dispersing oils
- I had to stick blend the pigments and TD for quite a bit because I had not dispersed them, so it was harder to get them to mix.
3. Layers separating
After I made this soap, I watched one of Amanda Aaron’s videos on a charcoal line soap. She explained that if your line is too solid, it can cause separation of the layers. I wish I had watched this sooner! The glitter layer, though barely visible, is causing separation in a couple of the bars. Maybe I should have sprayed with alcohol before pouring second layer.
4. Unmolding
This recipe is 64% hard oils, after 24 hours approximately, I unmolded. The sides were sticking to mold but the actual soap was hard and it gave me resistance while cutting with knife.I did not use sodium lactate, but I should have. or plain salt to the lye water. Why do I keep forgetting? I will add it to my recipe notes. I used this exact same recipe in my Emerald City inspired soap, and the results were very different. I will cover that in the next post.
Here is a link to the recipe And the video of the making of the unicorn soap.
Soaps by Glenda 
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