The old superfat after trace CP argument

[Kittish]

*raises hand* ok I'm going to ask for for all of the other newbies around here, other than acting as a buffer to make sure that the lye has something to eat and not make lye heavy soap what is the point in adding oil after cook in hot process or adding oil at trace? Also how would you super fat a soap (with a specific oil) before you SB everything? I just a bit loss :/

It's probably along the lines of 'hot process soap doesn't need to cure' in that it turns out to be not quite what was generally believed that adding oil after cooking lets you choose a specific fat as your superfat in HP. Nevertheless, lots of people believe it (just like lots of people believe that HP soap doesn't need to cure), as well as apparently believing that adding your superfat oils at trace means that that specific oil will be the bulk of your superfat. In other words, no real point as it turns out. I've learned something new here, too.

For the second question, short answer is you can't.

 

[seven8soap]

One weird thing is that even my “bad” soap is amazing after 6 months of curing. I made a ton of goat milk soaps this summer, and, well, stored it away thinking it was junk. Nope. I was wrong, it’s, you know, the best soap ever. And cheap, wholly moly, less than a dollar a bar for some really great stuff. I’d really like to see the breakdown of what a bar molecularly looks like at longer time intervals. There’s a theory that soap with butters needs a solid 6 month cure time to be at its best, so maybe that has to do with restructuring. The best test would be to see the structure of triple milled soaps, with or without added oils, as the structures are utterly destroyed in the milling process.

 

[Susie]

It's saved in my documents on my computer in my special 'DeeAnna File'. :mrgreen:


IrishLass

I thought I had it with the rest of them, but something happened to that file, and I am missing about three of those awesome explanations.

DeeAnna-you should add that lye party explanation to your blog. It is the best explanation of superfat ever.

 

[DeeAnna]

I have already edited this post and added it to my "soapy stuff" articles: http://www.soapmakingforum.com/showpost.php?p=634104&postcount=51. I'd forgotten about the post I wrote explaining why soap is alkaline -- http://www.soapmakingforum.com/showpost.php?p=394531 -- I need to add that it to my articles too. I see at the time this thread was active that I was still in love with shampoo bars, but I've since changed my tune. I eventually cut off a bunch of my hair even though I was using an acid rinse. The rinse slows down the damage, but doesn't stop it. I think I also have another post where I talk about the saponification party -- I'll see if I can hunt it up on my hard drive.

***

As far as the idea that superfat added after a hot process (HP) cook will then remain unchanged in the soap forever 'n ever -- this idea is not entirely correct from the bits and pieces I've put together.

In the second link I gave above, I talk about a dynamic equilibrium:

"...The resulting bar of soap is not a boringly static, unchanging block of stuff.... The chemistry going on ... is constantly changing -- it's like a huge party where all kinds of microscopically tiny people are circulating around. Some people "hook up" with each other and some just cruise. Some may hook up, but later unhook, cruise for awhile, and hook up with someone different.

"In chemistry terms, all this partying and circulating is called a "dynamic equilibrium". Obviously, many soap particles are created when the fatty acids and the sodium ions "hook up" more or less permanently to form the chemically neutral molecules we call soap. But there are also the chemical loners who circulate in the watery liquid inside the soap structure -- these include some sodium ions (Na+), some fatty acid ions (Ste- [stearic acid] and others), and the H+ and OH- [hydrogen and hydroxide] ions released by the lye and the fatty acids...."

This dynamic equilibrium also affects the fats remaining in the soap. Remember that soaping fats have three fatty acids and a glycerin. An alkali such as NaOH can break off the fatty acids reasonably easily -- we call this chemical reaction "saponification" and the result is soap. It turns out something as simple as water can break a fat molecule apart too. The chemical reaction of fat with water is called "hydrolysis" (hi-draw-luh-sis). The ultimate result of hydrolysis is a mix of free fatty acids, glycerin, and partly deconstructed fat.

Hydrolysis under normal conditions is slower than saponification, but it still happens. If the fat happens to be the superfat in a bar of soap, that super-duper deluxe expensive miracle oil you originally added to the soap will not stay intact. It will be gradually changed by hydrolysis into simpler chemicals that aren't anything like the original fat.

How fast does this transformation happen? As with so many soapy things, the answer is "it depends." Saturated superfat and monounsaturated superfat are more likely to remain mostly intact for a longer time; polyunsaturated superfat probably won't last as long (many exotic miracle fats are polyunsaturated). Anything that slows down rancidity (DOS) will also slow down hydrolysis, so antioxidants and chelators (ROE, EDTA, citrate, etc) and cool, dry, dark storage conditions may all help.

The bottom line is superfat added to HP soap after the cook will remain more or less in its original form for awhile, but it will not remain intact forever.