Cure time...

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And mine. I can not begin to tell a newbie how much better a 4 + month old soap is than a 4 week old soap is. The difference is astounding. There is, indeed, far more going on than moisture loss. When I made so many soaps for everyone, I stuck a note in there suggesting what order to use the soaps in based on the date they were made.

Reorganizing the drying rack last night I came across a disc of soap shaped like the bottom of a yogurt container which was the overage from a soap I made my mother and aunt for Christmas 2015. It was near the back on a low shelf, so I'd forgotten it was there. To have been ready for Christmas, I must have made it in September or October of 2014, so around 16 months old. Took some into the shower this morning and it's fantastic, just great. No substitute for time.
 
Actually, if we are talking shorter term than that, 5% KOH in the mix can jump your 6 week old soaps into 3-4 month old lather. But I would never try to give away or sell anything younger than that without it being to soapy people who understand how soap changes with a proper cure.
 
Susie, does KOH up the lather that much in "regular" soap? I use it exclusively for shaving soap, but have never used it for general purpose soap. If that is the case, I will have to try it.
 
Not Susie -- But, yes, that's what Susie is talking about -- adding a titch of KOH to regular soap you'd use for bathing! Yep, it really does work, especially with soaps that are high in oleic acid (olive, avocado, and other high oleic oils) or stearic and palmitic acids (lard, tallow, palm).
 
At first, I thought it was simply boosting lather in the soaps, and did not think about how my other soaps' lather changes with time. Then I found a 4 month old bar. The 5% KOH makes the lather of a 6 week old soap like a 4 month old soap. Same bubble structure, same density. I do not know what the longer term effects of the KOH are on the bar soap, but you can rest assured I will be testing it as soon as I can get some bars old enough to test. And with me about to start selling, the fact that I can have that wonderful lather in 6 weeks as opposed to 4 months is all to the good.
 
At first, I thought it was simply boosting lather in the soaps, and did not think about how my other soaps' lather changes with time. Then I found a 4 month old bar. The 5% KOH makes the lather of a 6 week old soap like a 4 month old soap. Same bubble structure, same density. I do not know what the longer term effects of the KOH are on the bar soap, but you can rest assured I will be testing it as soon as I can get some bars old enough to test. And with me about to start selling, the fact that I can have that wonderful lather in 6 weeks as opposed to 4 months is all to the good.
First I have ever heard of mixing KOH with NaOH like this.

Please tell me what to do to the recipe for replacing NaOH with KOH?

I assume I calculate the 5 percent of regular lye in soap calc and replace it with KOH?

What about the rest of the recipe, etc.?

Thanks for any info or links.

Oh, I received an order for NaOH from Essential Depot last year and they mistakenly put six 2lb jars of KOH in it instead of NaOH..........They were cool about it and told me to just keep the KOH.

I made some liquid soap with it, (more than enough for us at home for YEARS)............so I have about 8lb of KOH just lying around doing nothing!!
 
First I have ever heard of mixing KOH with NaOH like this.

Please tell me what to do to the recipe for replacing NaOH with KOH?

I assume I calculate the 5 percent of regular lye in soap calc and replace it with KOH?

What about the rest of the recipe, etc.?

Thanks for any info or links.

Oh, I received an order for NaOH from Essential Depot last year and they mistakenly put six 2lb jars of KOH in it instead of NaOH..........They were cool about it and told me to just keep the KOH.

I made some liquid soap with it, (more than enough for us at home for YEARS)............so I have about 8lb of KOH just lying around doing nothing!!


Um... I'm lazybones so I just use www.soapee.com or http://summerbeemeadow.com/content/advanced-calculator-solid-cream-or-liquid-soaps

Just note that KOH is not always come in 100% purity. And you should check out your supplier's purity.

Hope Other people with better math skills and using only soap calc will come in. :p
 
Thank you Cherrycoke and Susie!

I used the soapee calculator and it gave the amounts of KOH and NaOH to use with a 5%, 95% ratio.

Is everything else the same in terms of making the soap after dissolving the lye into the water?
 
Okay, here's my answer to Newbie's question in Post 36. In a nutshell, she asked, "...is the organization of the molecules dependent on the process of evaporation?..."

My answer is long and more complicated than what I usually write. But please don't anybody whine at me that it's harder than usual to digest. I can't think of any better, shorter, or less complicated way to explain this. So here's today's dose of soapy chemistry --

***

First some explanations of what a bar of soap really looks like if we could peek inside with a microscope --

A bar of soap is a complex mixture of solid crystals entirely surrounded by a film of liquid. The crystals are made of soap molecules fastened together in various 3-dimensional arrangements. Crystals can be big or small, and long or chunky. They can form many different shapes -- plates, irregular blocks, or even long spears.

In a hand-made superfatted soap, the film of liquid surrounding the crystals is a complex alkaline mixture of water, glycerin, and other water soluble chemicals as well as an assortment of dissolved soap molecules. There is a similar liquid inside the crystals as well, but for the purpose of this discussion, the liquid in the crystals is not as important as the liquid surrounding the crystals.

I want to stress this point -- Even though we tend to think of a bar of soap as a dry solid, it's actually a unique mixture of solid particles and liquids. The liquid in a bar of soap is just as important to the overall performance of the soap as are the crystals of solid soap....

Now I want to explain more about the individual soap molecules within this bar of soap --

Remember that a soap molecule is a fatty acid ion combined with a sodium ion. Fatty acids in handcrafted soap usually come from fats. Any given fat is a blend of several kinds of fatty acids.

When a batch of soap is made from fat, the soap molecules within the soap will vary in size and shape, depending on the different fatty acids in the soap. The most common fatty acids for soapmaking, from the smallest in size to the largest, are myristic, lauric, palmitic, stearic, and oleic.

Fatty acids with a simple straight shape are myristic, lauric, palmitic, and stearic. Soap molecules based on these fatty acids pack tidily into a soap crystal. Each kind of soap molecule has different chemical properties. For the purpose of this discussion, I want to share that myristic and lauric soaps are the smallest and are highly soluble in water. Palmitic soap is of medium length and is moderately soluble in water. Stearic soap, the longest molecule, does not dissolve well at all in water.

Last but not least is oleic soap. It is different than the others. An oleic soap molecule is the same overall length as stearic soap, but it contains a double carbon bond that twists the oleic soap molecule into a "U" shape. This bulky shape prevents oleic soap molecules from fitting nicely into the structure of a soap crystal, so the liquid phase in a bar of soap contains many more oleic soap molecules than what you might think from looking at the soap recipe.

When you wash with a bar of soap, the wash water penetrates the surface of the bar and mixes with the liquid phase. The very first soap molecules that touch your skin are the molecules dissolved in the liquid phase.

As you continue to rub the bar with your hands or washcloth, the abrasion removes soap molecules from the soap crystals as well as from the liquid phase. The soap molecules in the liquid phase are often distinctly different than the soap molecules in the crystals. This difference between the liquid and solid phases affects how the soap performs at the sink or in the bath....

So how does all this relate to curing soap?

When a bar of soap is newly made, the soap crystals contain a jumbled mixture of myristic, lauric, palmitic, and stearic soaps with a fair number of oleic soap molecules squeezed into the crystals for good measure.

The liquid phase surrounding these young crystals is large, and it also contains a jumbled mixture of soap molecules. Oleic soap molecules will predominate in the liquid phase due to their bulky shape, but there will be a fair number of all the other soap molecules in the liquid, including nearly insoluble stearic and moderately soluble palmitic soaps.

When you begin to wash with a young bar of soap, it is often the case that the soap will not lather well at first. This is true even though the young soap is relatively soft and contains a fairly large amount of water. The reason for the poor lather is the larger amount of less soluble and less bubbly stearic and palmitic soap molecules in the liquid phase in proportion to the more soluble myristic, lauric, and oleic soaps.

The amount of lather usually increases as you keep rubbing the bar, because you are scrubbing more soap molecules off the soap crystals. These molecules from the crystals mix with the soap molecules from the liquid phase. As more soap molecules accumulate on your skin or washcloth, they will build a larger amount of lather.

Fast forward to the end of the usual cure time of 4-6 weeks. By this time, the water content in the bar of soap has dropped -- it might now be 50% to 70% of the water that was originally in the soap bars. The glycerin and other water soluble chemicals in the liquid phase are left behind and become much more concentrated in the liquid phase.

All that seems plenty good from a human point of view -- evaporate excess water in the soap, leaving behind the soap molecules and other non-water chemicals. The cure is done, right?...

It turns out the process of curing is more subtle than that.

The high concentration of glycerin and other water-soluble chemicals in a bar of handcrafted soap has an unexpected effect on the liquid phase of the soap. Glycerin, along with as table salt and certain other chemicals, has the ability to "salt out" soap when the glycerin concentration becomes high enough.

During salting-out, soap molecules will not remain dissolved in the liquid phase. Instead, the soap molecules will coalesce into solid soap crystals. (I have described how the process of salting-out can be used to clean up soap scraps -- http://classicbells.com/soap/saltOutTut.html)

Not every kind of soap molecule will salt-out to the same degree. Stearic and palmitic soaps salt-out quickly and well. Myristic and lauric and oleic soaps do not salt-out nearly as easily.

What this means for a bar of soap is this --

As the glycerin and other dissolved chemicals in the liquid phase become sufficiently concentrated, the stearic and palmitic soaps in the liquid phase will form solid soap crystals -- in other words, they want to salt-out. These soap molecules also gradually trade places with lauric, myristic, and oleic soaps in existing crystals.

As time goes on, the crystals in a bar of soap will contain more and more of the less-soluble stearic and palmitic soaps and the liquid phase will contain more of the soluble lauric, myristic, and oleic soaps. This shift in the kinds of soap molecules in the liquid phase usually creates a faster building, more abundant lather for a smaller amount of work. The larger amount of less-soluble soap in the soap crystals has the benefit of making the soap more resistant to wearing away from use.

The concentration of stearic and palmitic soaps in the solid crystals begins when enough water evaporates to trigger the salting-out process. But the migration of insoluble soaps into the crystals and the transfer of soluble soaps into the liquid phase is not a fast process. It arguably can take months for this migration to stabilize in a handcrafted bar of soap....

And that, in not a nutshell, is why curing soap is a complex process that goes beyond water evaporation. The glycerin and other dissolved chemicals must be concentrated enough so soap molecules start to salt-out. Only water evaporation will accomplish that task, so it is a necessary beginning to the curing process. But once sufficient evaporation happens, the slower process of restructuring the soap then begins.

Are there ways to force this shift in the crystal structure and the nature of the liquid phase? Yes, if you have the equipment. Commercial soap makers quickly dry their freshly made soap to the desired water content, and then mix the dried soap chips or noodles under pressure using a machine called a "plodder." The soap is then pressed or extruded into finished bars. With careful control of the drying and plodding steps, the soap will form the desired crystal structure.

For handcrafted soap makers, the most practical solution is to allow time to solve the problem.
 
Well, color me fascinated. I had never heard of adding KOH to increase lather over a short period of time. Since it softens soap, I would think that I might have to do a water discount, especially since I use some "soft" oils in my soap. Or does this small amount of KOH have little to no effect on soap hardness? I plan to do this in my next batch, so I hope someone answers this one before I do that in the next few days. I am finally getting in the routine of making soap well ahead of time after accepting that there is no substitute for time in curing. I ran across an old bar the other day, and it was fabulous. Hard with great stable lather, although the fragrance had faded quite a bit.
 
I want to love DeeAnna's post but the app won't let me. Thank you for putting so clearly into words what my brain understood (but didn't know why). Bravo!
 
.

Last but not least is oleic soap. It is different than the others. An oleic soap molecule is the same overall length as stearic soap, but it contains a double carbon bond that twists the oleic soap molecule into a "U" shape. This bulky shape prevents oleic soap molecules from fitting nicely into the structure of a soap crystal, so the liquid phase in a bar of contains many more oleic soap molecules than what you might think from looking at the soap recipe.

DeeAnna, first, THANK YOU so much for taking the time and trouble to work so hard on putting together an explanation of how soap crystals are formed and work and all that goes into that, in terms a layman with only rudimentary knowledge of science can comprehend.

Second, I know how difficult it can be to proof read a large body of work, so please understand that I am asking only for clarification of an apparently missing word or words in the above highlighted phrase. What was your original intent for the part in blue? Was the word 'Castile' left out, or was it something else like 'soap made with certain soft oils'.

I have not yet finished reading your essay, but will continue because I do value your expert knowledge and well formulated explanations so much. Once completed, I can assure you I will come back to this several times to enhance my understanding of the topic.

Thank you,

Earlene
 

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