# Cure time...



## DeeAnna (Jun 18, 2013)

One of the common questions that inexperienced soapers often ask is how can the cure time be reduced? The common response from more experienced soapers is that there are no reliable shortcuts to curing soap.

Part of the curing process involves gradual chemical changes that reduce the pH, increase the mildness, and increase the lathering ability. Another part of the cure involves the physical process of drying which increases the soap's hardness and its useful life and stabilizes the soap's size for ease of packaging.

The drying process can be accelerated some with good ventilation, low humidity, and gentle warmth. The soap must still be allowed to dry slowly enough so internal moisture has enough time to migrate to the surface. If soap dries too fast, the soap can "case harden," which means it develops a hard outer rind that seals the surface and prevents internal moisture from evaporating. The bars may also warp and distort.

I did a simple experiment this May and June to measure the weight loss from two soap bars. I assumed the loss was from water evaporating from the bars. 

One soap (all-veg) was made with high-oleic safflower, palm, and coconut oil with a dab of sunflower and castor (listed in order from the most to the least). The water phase was coconut milk and distilled water. I included the fat content in the milk as part of my oil phase and lye calculation. The rest of the coconut milk made up most of the water phase for my recipe. The vegan soap was made with a 30% lye solution concentration.

The other soap (beer-lard) was made from lard, HO safflower, coconut, again with a dab of sunflower and castor (again listed in order from most to least). The water phase was 100% beer, and I used a 33% lye concentration for this soap.

I used a CPOP method to saponify both soaps -- the molded soap was heated at 170 deg F for about 1 hour.

I stored the soaps out in the open on the counter in my bathroom. This bath gets steamy only once a day when DH and I shower; otherwise it gets good air circulation. It is a convenient place to do this experiment and safely out of the way of people and pets. The weather was cool and wet during much of this time. I weighed the soaps on a digital scale that reads to 0.1 gram.

Both soaps showed the same trend in weight loss. There was a big reduction in weight from day 1 (the day the soap was unmolded and cut) through day 14, a moderate loss from day 14 through day 34, and a much slower loss after that. For the math geeks, the data fit a logarithmic trend at R=0.99.

I suspect in the winter with low humidity in the house, the rate of moisture loss might be a little higher. Even so, I would say a good rule of thumb is to allow about a month for moisture levels to stabilize. That doesn't mean the soap is fully cured for the best lather and mildness (see my Post 11 below for more on that), but it does mean the soap won't change much in size and the moisture content will be reasonably stable.


----------



## robtr31 (Jun 18, 2013)

I included the fat content in the milk as part of my oil phase and lye calculation. 

how do you do this ? on the soap calculator


----------



## Moody Glenn (Jun 18, 2013)

DeeAnna, I think this is one of the best summaries I have read on why a long cure is necessary. Your measurements of the actual process is wonderful. Excellent work! :clap:


----------



## DeeAnna (Jun 18, 2013)

Robtr31 -- you don't do it in your soap calculator. You create the recipe you want, then do some separate measuring and calculating. 

If you make your own coconut milk, you're on your own. I can't help!  If you are using purchased coconut milk, I can help. Here's how I figured the amount of coconut oil that was added by my coconut milk:

Read the nutrition statement on the can of coconut milk. Look for two things -- how many servings there are in the can of coconut milk and how many grams of total fat there are in each serving. 

Multiply the total servings by the amount of fat per serving. This will give you the total amount of fat in the entire can. Since this is coconut milk, you can safely assume all of the fat is coconut oil. My can of coconut milk contained a total of 45 g of fat. Important: Do not assume the fat in your coconut milk is the same. I looked at a can of coconut milk made by a different company and found it contained almost double the fat that was in the can I actually used.

If the can label tells you the total amount in FLUID OUNCES or MILLILITERS, you will need to weigh the contents of the can. My can contained 400 mL of milk that weighed a total 393 grams. I used the whole can in my soap. The can added 45 grams of fat and 348 grams of mostly water to my soap recipe. (393 g - 45 g fats = 348 g water and other stuff) 

I needed a total of 462 grams of water for my recipe. Since 348 grams of mostly water were in the milk, I only added another 114 grams of distilled water. (462 g - 348 g = 114 g)

I needed to add a total of 250 grams of CO, but 45 grams were coming from the milk, so I weighed out another 205 grams of CO. (250 g - 45 g = 205 g)

Hope this helps!


----------



## soapguy (Jun 18, 2013)

DeeAnna, is there a reason you selected your bathroom for the place where the rate of evaporation was to take place? Just curious. I ask because I recently moved my soaps out of the bathroom for fear that it was hindering the curing process. Now my soaps are located near a dehumidifier with a fan constantly blowing on them.


----------



## DeeAnna (Jun 18, 2013)

You assume I am as interested as you in optimizing my cure time, but that's not my focus. 

My goal is to gather useful information about my soap in the normal home environment. People don't store and use soap in a dehumidified space with constant air flow. They store soap in a closet, pantry, cupboard, or bathroom and use it in damp or wet spaces. 

If my soaps get DOS, so be it. I want that feedback. If it takes a few days longer to stabilize the moisture content, so be it. I want to know that too. If my soaps do fine for me under these conditions, then I know they will be fine for pretty much anyone else. 

If and when I ever go commercial (yeah, right!!!! :-?) then I assure you I will use the information I am gathering now to design a lovely and very effective curing space.


----------



## soapguy (Jun 18, 2013)

Actually, I made no assumptions about your interest in conducting this experiment. I merely asked because I was interested in extending the life of my soap, and yes, maximizing my curing time. But I understand that your experiment has value for those that keep their soap humid conditions, or live in countries where humidity is inescapable.  Curing time is important to me and the more I read the less convinced I am that the six week waiting period is as important as most people think. Yes, I agree that the longer you wait the better the soap will be, but not all soaps are created equal and depending on your lye, water and oil mixture I feel the curing time can be shaved off by a couple of weeks in many cases. I can't ask you to repeat your experiment, but I hope that someone will conduct the same experiment with a control group in non damp conditions. Who knows? It may put a end to the question of " how long does a soap need to cure?"  I do thank you for your efforts in bringing light to curing times in damp conditions.  I know it has helped me immensely.


----------



## Ruthie (Jun 19, 2013)

IMO the cure question has already been answered, and DeeAnna's experiment just proves it all the more.  Soapmakers have been experimenting and perfecting their methods for eons.  I started soapmaking 10+ years ago with all HP so I could use it the next day.  But now I let my soap cure, and it is better soap for it, whether HP or CP.  That is the "proof" I need.

Still, experimenting is fun.  So go ahead and try various cure and non-cure senarios.  I'm sure the answers will be interesting (and probably re-inforcing!)


----------



## soapguy (Jun 19, 2013)

Ruthie; I too have been making soap for many years, and I agree with the premise that a longer curing time will make a better soap. However  I believe the ingredients used dictate the curing time necessary. There comes a time in the curing cycle where time in curing has a minimal effect in curing. I have found that 3 to 4 weeks is a reasonable curing time for the soaps. Given that, I tend to stay away from soft oils and use Coconut oil in my recipes. Coconut oil is great as it has been shown to retard DOS. I have no scientific proof that keeping a soap in a non humid environment and away from heat will expedite curing times, but it just makes sense to me. I recently purchased a dehumidifier and expect it to be an asset when it comes to helping with the evaporation process. The one thing that is obvious to me is that there is no consensus on how long soap needs to cure. But without a truly scientific study for measuring the curing time for every possible ingredient and oil combination, any evidence provided is anecdotal at best.


----------



## roseb (Jun 19, 2013)

Well I'm convinced...I'm off to put some of my new batch in the bathroom!  Let you know what happens.


----------



## DeeAnna (Sep 29, 2015)

Here is an edited version of something I posted in another thread that expands on the idea of cure being more than water evaporation --

Any *solid soap needs time for three things to happen -- to finish saponifying, to evaporate excess water, and to develop a crystal structure*. Even if your recipe is designed to make a long lasting, mild, lathery bar, you will see the best of these qualities when you use a soap that is given enough time to fully cure.

The first aspect of cure is to complete the last lingering bits of saponification. When you unmold a soap, the saponification might be 99.9% done, but it's good to allow that last 0.1% time to finish before using the soap. Anyone who has eagerly bathed with a freshly cut bar of soap and gotten some skin irritation has learned that lesson. (... Of course I've NEVER done that! ...) A few days should be enough to meet this goal for a properly made soap.

The second aspect of evaporation is the most visible process to us humans. Evaporation causes a bar of soap to lose weight, shrink somewhat in size, increase in hardness, and become somewhat less soluble in water. My first post in this thread talks about this aspect of curing.

The third aspect -- development of crystalline structure -- is a process that most people can't see and so they tend to ignore or discount this as not being important.

The crystal structure of a solid soap is made of soap molecules that tend to join up to form large sheets. (The soap molecules form other shapes as well such as balls and hot dogs, but please bear with my simplification.) Ideally, these sheets stack one on top of the other, just like slices of bread in a triple-decker sandwich.

In this ideal structure, the spaces between the sheets are filled with a alkaline liquid made of water, glycerin, dissolved soap, etc. This liquid is much like the filling in my triple-decker sandwich. Some of the alkalinity of this liquid is a natural consequence of lye soap being lye soap, and some may be bits of excess lye that will be saponified and neutralized during the first days of cure as mentioned above.

When a handcrafted soap is newly made, this soap structure is disorganized (small wonder after being wildly beaten up by a stick blender!) and there is a lot of free liquid floating around. This disorganized situation is a bit like a dry sponge lying in a puddle of water. You want the sponge to soak up the water to clean up the mess, but the process isn't instantaneous -- the sponge first has to get damp and then it can absorb the water. Same with soap -- the alkaline liquid needs to be "soaked up" and trapped within the soap structure, but it takes time at first to create an organized structure that can soak up the liquid.

A crystal structure of sorts is developed in commercial soaps by drying soap flakes under vacuum, extruding the flakes through dies, forcing the soap into a mold under pressure, and sometimes by (French) milling. Commercial soaps are also sometimes also given a certain amount of time to quietly cure on their own. Since we don't normally have the ability to artificially dry, extrude, mold, or mill our handcrafted soaps, our soaps can only be cured by the application of time. Once the soap becomes more crystalline, the alkaline liquid that is naturally a part of soap is trapped within the sheets of soap molecules, and the soap molecules themselves dissolve more slowly when the soap is used (in other words the soap becomes less soluble in water.) The soap thus becomes milder, in that the soap cleanses the skin without making the skin feel overly dry or "tight."

On a related note, the question is sometimes asked -- *Does liquid soap needs an equivalent cure?* Liquid soap doesn't have a defined crystal structure, and it doesn't need to dry. It's good to let liquid soap (whether it is in paste or diluted form) sit for a few days right after it has been made. This allows the last bits of saponification to finish up. Some soapers also let their diluted soap "sequester" for days to weeks so fine particles can settle out and thus improve the clarity. This is an optional step -- if a liquid soap looks fine, it's perfectly fine to omit this sequestering time.


----------



## dibbles (Sep 29, 2015)

This is very interesting DeeAnna. Thanks for doing the research and reviving the thread. As always, your explanation makes it so easy to understand.


----------



## spenny92 (Sep 29, 2015)

I was browsing the Dish forum (I don't post there as I find the forum intimidating, generally) and noticed several experienced soapers state that they use a steep water discount and consider their CP soaps cured after just a few days. If anyone mentioned that here, they'd be shot down in flames - I'm wondering why one group of people find that acceptable? I know the water disc will account for a harder bar, at least, but we all know that hard doesn't equate to cured.


----------



## Krystalbee (Sep 29, 2015)

Awesome read!
 When I started soaping,  I learned saponification and water evaporation happened during cure time. I have never heard that cure time also involves the  formation of a crystalline structure. I guess it goes to show there are always a myriad of things to learn... especially in soap making.
Thanks :-D


----------



## DeeAnna (Sep 29, 2015)

"...several experienced soapers state that they use a steep water discount and consider their CP soaps cured after just a few days. If anyone mentioned that here, they'd be shot down in flames..."

I agree -- the "cured in a few days" idea is something that pops up fairly often about CP soap made with concentrated lye solution and also about HP soap. It's weird that these two methods are supposed to give similar instant cure, because HP soap usually has MORE water than typical CP soap. I suspect the main assumption is "done saponifying" is the same as "cured." I don't get why this idea persists -- it's a matter that a soaper can easily check by testing a soap every week or three for some months to a year and keep careful notes. 

The soaps I tested (see chart in Post 1) were made with lye solution concentrations of 30% (vegan) and 33% (honey beer), so they are moderate "water discount" soaps. You can see for yourself that both took about 30-40 days to really slow down in their weight loss. The longevity in use and lather quality are other qualities of soap that can be easily evaluated. Even though these qualities are somewhat more subjective, it's still possible to learn that a soap can change quite a bit over time.

I think The Gent says it best -- something about a soap that's safe to use is not the same as a soap that is at its best. I think he says it a little more poetically, but I hope you get the drift.

So ... yeah ... I don't get it either, Spenny. :roll:


----------



## The Efficacious Gentleman (Sep 30, 2015)

'Safe to use' does not mean 'good to use'

I think the easiest example is Castile soap - it will stop losing water after a bit of time, but the difference between 1 month, 3 month, 6 month and 12 month old Castile is quite noticeable which means something is clearly happening other than water loss, at least in Castile.


----------



## spenny92 (Sep 30, 2015)

I agree. I just found it odd coming from such experienced soapers. They are sellers, too, so the point was more about them being ready for sale rather than just safe to use, which is kind-of crazy. I'm glad I found this forum first, if I'm honest!


----------



## DeeAnna (Sep 30, 2015)

I think this "instant cure" myth is the soaper's version of the classic "get rich quick" scam. Impatient soapers buy into it because it suits them to believe this is really true; the rest of us just wonder about what's going on.


----------



## ngian (Dec 24, 2015)

DeeAnna said:


> The third aspect -- development of crystalline structure -- is a process that most people can't see and so they tend to ignore or discount this as not being important.
> .



Doesn't gel phase speed up the development of crystalline structure and thus somehow this third aspect needs less time in contrast with a non gelled soap?


----------



## Susie (Dec 24, 2015)

Nope.  Cure takes the same amount of time for gelled as ungelled.  Try it, you will know then.


----------



## cmzaha (Dec 24, 2015)

spenny92 said:


> I was browsing the Dish forum (I don't post there as I find the forum intimidating, generally) and noticed several experienced soapers state that they use a steep water discount and consider their CP soaps cured after just a few days. If anyone mentioned that here, they'd be shot down in flames - I'm wondering why one group of people find that acceptable? I know the water disc will account for a harder bar, at least, but we all know that hard doesn't equate to cured.


I am also a member of the Dish. The majority there are into lotion making more than soap.


----------



## Saponista (Dec 26, 2015)

I tried to join the dish and they never authorised my account so I gave up.


----------



## penelopejane (Dec 26, 2015)

I think the difference between cured and aged soap is significant. When I first tried homemade soap I found it too soft and most of is washed down the drain so I gave up on it. 2 years later I tried the exact same soaps (samples still in my cupboard) and they were amazing. So much so that I started making soap for myself. 

I can see why people who sell soap don't want to store it but they are really doing themselves and the industry a disservice.


Saponista said:


> I tried to join the dish and they never authorised my account so I gave up.



Their loss, our gain.


----------



## Steve85569 (Dec 26, 2015)

I think of the cure tome as something along the lines of wine.
Once wine is done fermenting you CAN drink it ( tastes like rotten fruit). It is a lot better when you let it "cure" and even better when you let it "age" ( develops notes and a nice body).

Once soap is done saponifying you CAN use it ( cleans). But why do that when after it cures it improves in so many ways ( lather, body and conditioning )? If you have the patience to age a soap ( try this with a stable recipe) try it ( think Castile or salt bar).

Just my thoughts.

Steve


----------



## ngian (Dec 26, 2015)

Susie said:


> Nope.  Cure takes the same amount of time for gelled as ungelled.  Try it, you will know then.




I agree with you Susie, but I just wanted to say that maybe an ungelled soap will have the same crystallized structure with a gelled soap in maybe twice the cured time, and all this if we can somehow meter this formation (hardness, foaming behavior, the amount of water the bar can soak in, in a specific time just like Kevin Dunn did.)

I did the question in the first place because I've read that gel phase speeds up this formation (crystallized structure), while this structure (when the molecules of sodiums of the fatty acids are sitting next to each other as tidy and close as the can) is also being developed slower while the soap is in the cure phase.


----------



## edstewbob (Aug 31, 2016)

I know it's difficult to say for sure but as a general rule what would you suggest is a good rule of thumb for water loss percentage to consider a CP batch to be fully cured considering there has been no water discount applied to the batch? DeAnna's chart on page one suggests on the order of 8-9% water loss before it tapers off.


----------



## DeeAnna (Aug 31, 2016)

That's correct for the two batches I tested. I made these soaps with a 30% to 33% lye concentration. "Full water" using the usual default of 38% water as % of oils is roughly 28% lye concentration for a typical blend of fats. But "38% water as % of oils" can range in lye concentration from 25% to 31% if you make castile (olive) or "marine" (coconut oil) soaps. So what's your idea of full water? If it falls within the lye concentrations I've mentioned, then I'd say 8% to 10% water loss is a reasonable estimate. Bear in mind that the water loss can taper off and the soap might still not be considered fully cured.


----------



## The Efficacious Gentleman (Sep 1, 2016)

Even with the great work done by others, if I was looking to rely on something for weight labeling, I would test each recipe of mine myself. So many different things can impact the amount of water lost and the weight that it corresponds to that nothing short of actually weighing a soap regularly for a while will be accurate enough


----------



## TeresaT (Sep 2, 2016)

The Efficacious Gentleman said:


> Even with the great work done by others, if I was looking to rely on something for weight labeling, I would test each recipe of mine myself. So many different things can impact the amount of water lost and the weight that it corresponds to that *nothing short of actually weighing a soap regularly for a while will be accurate enough*


 

And so, that's what I started to do.  I used to use the standard "six week" cure time before I'd even use it, let alone think about giving it to someone.  But I started to weigh my batches.  I weigh 4 bars from each batch.  I write numbers on a label and rip it then stick it to the bars.  Primitive but effective.  I started doing that with all of my soaps in June because I wanted to track the weight loss to determine when it was "safe" to take them off the shelf and put them in a box.  I decided when I got three weekly readings in a row the same, then it was OK to pack them up.  The only problem with my "brilliant" idea is one out of four bars (different bars) in every batch lost 5 grams each time.  I decided it was my scale and/or not really significant enough weight loss to make a difference.  They're boxed and will sit in the boxes for six months to a year before I do anything with them.

I like a long cure.  I've tried my soaps that were old (six months to a year) and found them to be 100% better than they were when I made them.  That got me hooked on the idea that something else is going on with the soap on a molecular level and I made the wine comparison, too.  Like wine, I am convinced that soap gets better with age.  I have no proof of that, other than what DeeAnna has explained here, and there are so many soapers that say completely different information regarding curing and what exactly it is.  

I know what it is not.  Curing is not saponification and water loss.  There is something far more going on.  One of the things I noticed, and was pleasantly surprised about, is it is far easier to "clean" up an old bar of soap than a new bar of soap.  When I'm planning my weeks old soap to box them, they smear all over the planner.  When I grabbed old soap that had never been planned, it flaked and crumbled.  It was much easier to work with.  Actually, I'll have to remember that.


----------



## IrishLass (Sep 2, 2016)

TeresaT said:


> I know what it is not. Curing is not saponification and water loss. There is something far more going on.


 
Exactly my experiential observations as well!


IrishLass


----------



## Susie (Sep 2, 2016)

IrishLass said:


> Exactly my experiential observations as well!
> 
> 
> IrishLass




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.


----------



## Steve85569 (Sep 2, 2016)

Susie said:


> 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.



Add my name to the list.
At 4 to 6 weeks most soap is usable. At 4 to 6 months most soaps are getting a lot better. Saponification takes a few hours so you gotta know there's something beyond that that is happening. 

Maybe it's just soapy magic!


----------



## edstewbob (Sep 5, 2016)

Is it possible to have too long a cure time where the quality of the soap is degraded? I'm thinking specifically of the oil that has not saponified due to whatever superfat percentage was selected might turn rancid over time and we don't have a lot of choice especially in CP which fats remain in the soap.


----------



## Susie (Sep 5, 2016)

I have a small piece of the first soap I made in 2013.  So far no rancidity.  And it is AWESOME!


----------



## shunt2011 (Sep 5, 2016)

I agree with the others. There is some soapy magic happening with a really well cured bar of soap. I just found one of my very first bars in a drawer form 2010 and it still smelled good and lathers great. It wasn't the best recipe but it's better now than when it was made. 

That's one of the biggest reasons I try to make the bulk of my soaps in the winter for my spring and summer shows. However, it's proved to be that I under estimated things badly this year. My business has picked up a whole lot and. I've been hustling to keep enough stock in place. With at least a 6 week cure. I really prefer longer.  Will be better prepared next year I hope


----------



## newbie (Jan 13, 2017)

Someone was posting in a soap forum about cure and it being only as long as water evaporation so I made a comment about it also being about the structuring of the soap. I posted one of your explanations, DeeAnna, which they felt was very helpful (I said this was not my own answer) and someone had the following questions.

"What is the relationship between water evaporation and the formation of the crystalline structure? I assume that to some extent, they go hand in hand. In other words, if you kept a newly formed bar of soap in a small sealed container, so that there was no place for the water to evaporate to, would the crystalline structure still form? Does it form faster when there is less water to begin with? Or does the water play no roll at all, and the crystalline formation is completely independent of the water in the soap. THIS is a question I've had for a long time."

Given that we can soap with a fair water discount, clearly not all the water is necessary, but is the organization of the molecules dependent on the process of evaporation? And her other questions.


----------



## Susie (Jan 13, 2017)

I do not soap with a water discount.  I have the same question, but my gut tells me that loss of moisture has very little to do with formation of crystalline structure as my soaps continue to improve long after they stop losing moisture weight.


----------



## newbie (Feb 12, 2017)

Bump! I think DeeAnna is back from vacation.


----------



## DeeAnna (Feb 12, 2017)

Hey, Newbie -- I've been working on an answer, but it's turning into "War and Peace." I'm about 2/3 done....


----------



## newbie (Feb 12, 2017)

Oh my! Well, I thank you prematurely for your answers. They are always well-thought out and very well-explained. I really appreciate that you take the time and effort to do it.


----------



## BrewerGeorge (Feb 13, 2017)

Susie said:


> 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.


----------



## Susie (Feb 13, 2017)

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.


----------



## beckster51 (Feb 17, 2017)

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.


----------



## DeeAnna (Feb 17, 2017)

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).


----------



## Susie (Feb 17, 2017)

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.


----------



## RDak (Feb 19, 2017)

Susie said:


> 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!!


----------



## cherrycoke216 (Feb 19, 2017)

RDak said:


> 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?
> 
> ...




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.


----------



## Susie (Feb 19, 2017)

cherrycoke216 said:


> 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.



Nope-I use soapee.com also.  Just makes life much simpler when I do not have to do math.


----------



## RDak (Feb 19, 2017)

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?


----------



## cherrycoke216 (Feb 19, 2017)

RDak said:


> Is everything else the same in terms of making the soap after dissolving the lye into the water?



Yes I did everything else the same way i did normal NaOH soap. Have not had a problem. ( knock on wood )


----------



## DeeAnna (Feb 19, 2017)

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.


----------



## newbie (Feb 20, 2017)

OMG, DeeAnna! I cannot thank you enough for all the effort and time you put into this. I think you should put up your explanation of what cure is about, with this part, as an article on your website.


----------



## dibbles (Feb 20, 2017)

As always, DeeAnna, a very thoughtful and interesting read. Thank you!


----------



## Susie (Feb 20, 2017)

Awesome answer, DeeAnna!  Even I understood it!

Can someone please sticky this answer so that every time someone wants to use a dehydrator to speed cure, we can point them to it?


----------



## The Efficacious Gentleman (Feb 20, 2017)

DeeAnna drops the mic.  Boom!


----------



## beckster51 (Feb 20, 2017)

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.


----------



## BrewerGeorge (Feb 20, 2017)

Outstanding, DeeAnna!  So with that in mind, how does the KOH increase lather/decrease snottiness early in the cure?


----------



## amd (Feb 20, 2017)

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!


----------



## earlene (Feb 20, 2017)

DeeAnna said:


> .
> 
> 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


----------



## kchaystack (Feb 20, 2017)

BrewerGeorge said:


> Outstanding, DeeAnna!  So with that in mind, how does the KOH increase lather/decrease snottiness early in the cure?



I think this is where she talks about it.  http://www.soapmakingforum.com/showthread.php?t=59747


----------



## BrewerGeorge (Feb 20, 2017)

kchaystack said:


> I think this is where she talks about it.  http://www.soapmakingforum.com/showthread.php?t=59747



Oh, yes, I've seen that! I was asking more about what KOH does in the context of the explanation above. How does it affect the crystal and liquid colloid that DeeAnna described?


----------



## Millie (Feb 20, 2017)

Thank you DeeAnna!


----------



## HowieRoll (Feb 20, 2017)

Thank you so much, DeeAnna, for all the obvious hard work you put into making that a reader-friendly, information-packed explanation.  I will be re-reading it a few (or several) times, but my initial thoughts were that it sure cleared up many questions I'd had about soap structure.  You rock!


----------



## DeeAnna (Feb 20, 2017)

*Earlene* -- 

I wrote: "..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...."

And you asked "...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'm talking about any soap that contains any amount of oleic acid. Even a 100% coconut oil soap contains oleic acid -- about 8% according to my notes. 

But you're right -- I see I need to add "soap" after "bar of" in that sentence. Thanks for bringing this to my attention -- correction made.

*BrewerGeorge* -- you asked another short, apparently simple question that needs a long-winded answer. Lemme work on it, okay?


----------



## IrishLass (Feb 21, 2017)

Thank you _so much, _DeeAnna, for putting into words what all of the long-term soap-makers here had discovered for themselves and known for a long time from _tangible experience_, but were just not able to explain from a scientific perspective, especially in such a wonderful, well written/easy to grasp manner! Bravo and thank you, thank you, thank you! You are amazing and deserve a hearty round of applause!




I eagerly await your "long-winded" answer to Brewer George! 


IrishLass


----------



## DeeAnna (Feb 21, 2017)

Thank you, Irish Lass and everyone else! 

I'm still plugging away on BG's answer. I've been reading and re-reading several tomes on soap chemistry and technology to glean the info I need for the questions in this thread. Distilling the science down to everyday language is a good way to learn a subject like this, but it's slow work.


----------



## IrishLass (Feb 21, 2017)

No pressure- it's worth the wait!


IrishLass


----------



## CaraBou (Feb 22, 2017)

How cool is THAT to understand what happens inside a bar of soap! Maybe some day we'll have microscopy pics showing actual molecular structure at various stages. No pressure DeeAnna ;P


----------



## newbie (Feb 22, 2017)

Is there any difference in this scenario if there is a water discount? I would assume that there is still water to be evaporated before the salting out reaction is triggered, but that it may be triggered somewhat earlier. From the sounds of it, this organization takes many weeks to complete, so water discount would not change the fact that 4-6 weeks of cure time is needed (more for this structuring to complete.)


----------



## Spice (Feb 22, 2017)

DeeAnna said:


> "...several experienced soapers state that they use a steep water discount and consider their CP soaps cured after just a few days. If anyone mentioned that here, they'd be shot down in flames..."
> 
> I agree -- the "cured in a few days" idea is something that pops up fairly often about CP soap made with concentrated lye solution and also about HP soap. It's weird that these two methods are supposed to give similar instant cure, because HP soap usually has MORE water than typical CP soap. I suspect the main assumption is "done saponifying" is the same as "cured." I don't get why this idea persists -- it's a matter that a soaper can easily check by testing a soap every week or three for some months to a year and keep careful notes.
> 
> ...



Why in the world would anyone want to "shot down in flames"?? Maybe this is why I am having a time posting....fear. Not all soap makers are created equal. Not all situations are perfect, and.....to create takes guilts. Stepping out of the norm should be a, "Wow, I never thought of that".


----------



## BrewerGeorge (Feb 22, 2017)

Spice said:


> Why in the world would anyone want to "shot down in flames"?? Maybe this is why I am having a time posting....fear. Not all soap makers are created equal. Not all situations are perfect, and.....to create takes guilts. Stepping out of the norm should be a, "Wow, I never thought of that".



The frustration that might lead to those shots being fired comes from the regularity with which this subject returns.  There is SO much bad info on the web and in social media.  Not a week goes by that I don't see at least one post on a homesteading or prepper facebook group with a bad article about making soap.  (Usually they're not dangerous, just bad recipes, process, and advice.)  

There are a lot of so-called experts out there leading people in the wrong direction.  Soap making is forgiving enough that people can have "success" simply parroting a flawed process without ever really knowing what they're doing or, indeed what they're missing.  But on this site, there are several people who really, _really_ know what they're doing (Please note that I am *not* including myself in that...) and are willing to share that knowledge for the greater good.  So when the next person shows up asking why HP soap needs to be cured like CP soap, the response may be ...quick.

However, I do not think I've ever seen those shots fired in anger here.  This is a welcoming place.


----------



## Scooter (Feb 22, 2017)

BrewerGeorge said:


> The frustration that might lead to those shots being fired comes from the regularity with which this subject returns.  There is SO much bad info on the web and in social media.  Not a week goes by that I don't see at least one post on a homesteading or prepper facebook group with a bad article about making soap.  (Usually they're not dangerous, just bad recipes, process, and advice.)



Also, the home-based artisanal soap business is not closely regulated, at least not in the USA. I don't sell soap myself but if I did I would resent someone else selling bad soap. A customer who goes down to the local farmer's market and buys soap that irritates her skin may decide that all artisanal soap does that and not buy any ever again--from anyone, including from the people who know what they're doing.

So I see some of the negative reaction to bad soaping advice on this forum as a way for people to make sure the soap-making community maintains some quality standards.


----------



## cmzaha (Feb 22, 2017)

newbie said:


> OMG, DeeAnna! I cannot thank you enough for all the effort and time you put into this. I think you should put up your explanation of what cure is about, with this part, as an article on your website.


I agree ^^^. Thankyou DeeAnna



Scooter said:


> Also, the home-based artisanal soap business is not closely regulated, at least not in the USA. I don't sell soap myself but if I did I would resent someone else selling bad soap. A customer who goes down to the local farmer's market and buys soap that irritates her skin may decide that all artisanal soap does that and not buy any ever again--from anyone, including from the people who know what they're doing.
> 
> So I see some of the negative reaction to bad soaping advice on this forum as a way for people to make sure the soap-making community maintains some quality standards.


I have had quite a few people visit my booth thoughout my years of selling and mention they would not use handmade soap, due to poor recipes or cure times. I have seen many a bad soap being sold in markets and it hurts all of us sellers. This is not including the people that simply cannot use handmade soap


----------



## Susie (Feb 23, 2017)

cmzaha said:


> I have had quit a people visit my booth thoughout my years of selling and mention they would not use handmade soap, due to poor recipes or cure times. I have seen many a bad soap being sold in markets and it hurts all of us sellers. This is not including the people that simply cannot use handmade soap



It even affects people who don't sell.  My own (ex)in-laws would not use my hand made soap because they got bad soap from somewhere.


----------



## The Efficacious Gentleman (Feb 23, 2017)

Not to mention that "stepping out of the norm" might also be a step in to something utterly and totally and demonstrably wrong, so the reaction can't and shouldn't be "wow, I never thought of that" particularly if someone had thought of that, tried it and/or crunched some science and found it to be false. 

As in your example, someone who says "curing is finished when the water is evaporated therefore I use a steep water discount to get cured faster" can't then explain a Castile cure or a salt bar cure. I can't say "wow" to that. 

I think that the major issue is that people often put these things out as being a fact. The flames of that need be put out before they can spread - bad information spreads online like wildfire.


----------



## reinbeau (Feb 23, 2017)

DeeAnna, awesome info.  You need to write a book - or someone needs to cull through all your posts in SMF and assemble them into a book for you!


----------



## CTAnton (Feb 23, 2017)

DeeAnna....you're simply priceless!


----------



## IrishLass (Feb 23, 2017)

reinbeau said:


> DeeAnna, awesome info. You need to write a book - or someone needs to cull through all your posts in SMF and assemble them into a book for you!


 

Well, I haven't assembled a DeeAnna book or anything like that, but I confess that I have a 'DeeAnna Files' folder on my computer into which I copy/paste the links to all of DeeAnna's posts on the forum that have specifically answered many of the nagging/curious questions I've had about the secret life of soap over the years. I got the idea from Susie. :mrgreen: 

IrishLass


----------



## Spice (Feb 24, 2017)

DeeAnna, I do apologize for being rude, your work that you have done is great, I do follow you, and believe I was out of line. I don't know if I misunderstood what I was reading or I just didn't understand what I was doing. Either way, I apologize.


----------



## DeeAnna (Feb 25, 2017)

No apology necessary, Spice. I didn't think you were talking to me specifically -- more talking in general about your reactions and feelings. We're good!


----------



## beckster51 (Feb 27, 2017)

DeeAnna, The information that you provide to the forum is absolutely priceless!  I am a science geek, so I read all your posts with bated breath.  Thank you so much for giving us this valuable and fascinating information.  I truly appreciate it.


----------



## earlene (Feb 28, 2017)

beckster51 said:


> 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 haven't noticed if anyone answered your question above. Maybe it was answered & I forgot because I have kept coming back to this thread and only re-reading some of it and not responses every time.

 I have made only a few batches of 95% NaOH with 5% KOH bar soap, so take my response with a grain of salt.  No, it doesn't in such a low percentage.  In a higher percentage it does, but that is also dependent on your recipe.  As you can surmise, soaps with a higher percentage of hard oils would be less affected, whereas soaps with a higher percentage of soft oils would be more affected.

I tend to use more soft oils in most of my recipes and noticed a significant difference when I tried a 10% KOH/90% NaOH in softness of the resulting soap.  I expect a long cure will solve the problem eventually, but haven't looked back at those particular soaps in a while, so don't yet know.  I can only hope.

~ ~ ~ ~ ~

*DeeAnna*,  I have another question or two for you.  Please bear with me because my college chemistry days are long ago in my past, and although I thoroughly enjoyed and was fascinated by my courses, some of what I learned is now a hazy memory.

You mentioned a couple of phases that didn't quite ring a bell for me, so I did  a little searching online and in one book.  Still I find myself not clear on these phases.  Kevin Dunn has referred to the water phase at some point in his lectures and I found at least one mention in his book where he defines the liquid-crystalline phase as gel phase (Neat Soap, page 391 Scientific Soapmaking).  Other than that, I had a hard time finding something to help me really grasp these terms as they relate to curing soap.  Probably all I did by searching for answers is to become more confused.

So what is the liquid phase?  When you talk about it, you are talking about bar soap, that is solid bar soap already in the curing process.  So I'm not grasping the meaning of liquid phase in this context.  Please understand I am not trying to be difficult, I am trying to understand the concept of what _liquid phase_ means here.  I don't think it means gel phase as I understand liquid-crystalline phase to mean since we are talking about soap while it cures.  

And what is the water phase (in curing soap)?  Which comes first, or do they both exist simultaneously in different parts of the same bar of soap during cure?  I sort of think the latter is the case, but am unsure.

Earlene


----------



## Steve85569 (Feb 28, 2017)

Fascinating post and awesome answers!

I *think* I just learned a bunch....


----------



## DeeAnna (Feb 28, 2017)

The liquid phase is the fluid within and between the soap crystals in bar soap. You're talking like it only exists at certain times, but it is always there in soap regardless of its age. As water evaporates, the liquid phase becomes smaller in volume, that is true. But it never disappears.

***

The most common usage of the word "gel" for us handcrafted soap makers is what happens during CP or HP saponification when soap gets warm enough to turn from a solid form into a softer paste something more like Jello or peanut butter. What Dunn calls "neat soap" as opposed to "curd soap." This is the response of soap to an increase in temperature at a relatively constant water content. 

Although I think most soapers view this as the only "real" way that soap gels, this is is not really true. 

Soap can also change into a gel in response to changes in water content at a relatively constant temperature. Soap can become a gel even at room temperature, if sufficient water is added. Some soaps gel easier than others, however. An example of this is when oleic bar soap absorbs water to form a clear jello-like substance (aka castile slime). Or when someone tries to make "liquid soap" by grating bar (NaOH) soap and adding water. The resulting runny liquid can eventually restructure itself into a Jello-like gel. This is also "gel" just like the gel that results from higher temps.

***

You can think of bar soap as a really complex material with extra physical phases in addition to the usual solid and liquid (and gas) phases we normally expect to find - water being an example of something with uncomplicated phase changes.

Bar soap is solid when it is sufficiently cool and has not too much liquid in it so the soap crystals are fixed more or less in place. The point at which soap is a solid will vary depending on the fatty acids in the recipe.

Bar soap turns into a gel form when it is warm enough and/or contains enough water so the crystals are able to "unstick" enough so they can slide around each other. There are various forms of liquid crystals, so the flowable nature of a soap in gel can vary. Soap makers break Dunn's "neat soap" into several sub groups depending on the type of gel formed by the soap.

Bar soap becomes what's called an isotopic solution when sufficient water is added and/or sufficient heat is added so the soap in solid or gel form can break down into individual molecules. An isotropic solution is very fluid (runny). This is what happens to soap in your bath water.


----------



## Spice (Feb 28, 2017)

DeeAnna said:


> No apology necessary, Spice. I didn't think you were talking to me specifically -- more talking in general about your reactions and feelings. We're good!



Thank God!


----------



## earlene (Mar 1, 2017)

DeeAnna said:


> The liquid phase is the fluid within and between the soap crystals in bar soap. You're talking like it only exists at certain times, but it is always there in soap regardless of its age. As water evaporates, the liquid phase becomes smaller in volume, that is true. But it never disappears.
> 
> ***
> 
> ...



So when you were talking about the water phase previously (post #53 & #54), it was in reference to the liquid-solid-gas properties of the water phase?  That's what I thought at first, then doubted my assumption.  Or did you mean it as when we add water to the bar of soap to make it liquid again?  Now I am just getting confused again.  (So sorry to be hard to educate.  I've always had to ask a lot of clarifying questions when I don't grasp a concept.)

You are right, the word phase means something different to the layperson than it does to the scientist, I think.  I could be wrong, of course, but I think generally 'phase' in the layperson's mind is more like a time-related event.  Example: The kid is going through a phase (time limited and not constant.)

I am sure that is part of what is causing my confusion.  My scientific training is quite limited and I don't really recall much about simultaneous or co-existing  (not really sure what the right word here would be) phases.

You are right, I do know that there is liquid or water in soap bar soap at all times, but never thought of it as a phase, probably because of my non-scientific understanding of the word/concept of phase.

Thank you for taking the time to expand on this issue.

Earlene


----------



## DeeAnna (Mar 1, 2017)

I've corrected my earlier posts to only use "liquid phase" throughout. In two places I had carelessly written "water phase" when I should have written "liquid phase."

***

Lots of apparently solid things contain liquid, and soap happens to be one of them. When talking about bar soap, a loaf of bread, a hard boiled egg, or many other things of this nature, you can discuss the dry part of the material -- its solid phase -- or you can talk about wet part -- in other words, its liquid phase. 

What I mean by "liquid phase" is the liquid found inside an apparently solid, dry bar of soap -- this liquid originates from when the soap was made. This would be any liquid used to make the soap such as water, beer, fluid milk, etc; the glycerin made during saponification; any dissolved salts or sugars from the recipe; etc. "Liquid phase" does not mean the water added when you use the bar of soap to wash.

***

I get the feeling, Earlene, that you're confusing my talk of the "liquid phase" in solid bar soap with Dunn's discussion about "neat" soap. You can't take what he's talking about and apply it to what I'm talking about. To relate this back to a simpler example, Dunn is talking about "water" and I am talking about "ice". The same chemical but in two different physical forms.

You brought up the term "neat" soap but didn't seem to understand what it really meant, so I tried to explain what "neat" soap is. Here are examples --

---- Neat soap is what you get when you soak a bar of olive oil soap in water -- the Jello-like goop or slime on the bar is "neat" soap. 

---- Neat soap is what HP soap makers see when their soap looks like "vaseline" during the cook.

---- The thick paste that liquid soapers make as well as the diluted soap they make from that paste are both examples of "neat" soap. 

Again, "neat" soap can also be called soap in "gel" phase or it can be called a liquid crystal. It can even be called a colloid. It all means the same thing. What "neat" soap is NOT is a solid soap like a bar of soap. My earlier posts talking about curing bar soap (Posts #51-55) are only talking about solid soap.

***

I don't know if I'm answering your questions, Earlene. I'm not sure what I can say to make things clearer. Soap is complicated stuff.


----------



## beckster51 (Mar 7, 2017)

Earlene, thanks so much for your reply.  I found it very helpful and appreciate your courtesy!


----------



## DianaMoon (Feb 25, 2018)

I'd like to add my voice to the chorus of thank you's to DeAnna!


----------



## DeeAnna (Feb 25, 2018)

BrewerGeorge said:


> ... So with that in mind, how does the KOH increase lather/decrease snottiness early in the cure?



It's been almost a year, BG, but I still haven't forgotten your question. Finally, in a fit of inspiration (or insanity) today, here is my answer --

A basic soap molecule looks something like a Tootsie Roll Pop, especially if you look at soap molecules made from straight chain fatty acids (palmitic, lauric, stearic, myristic) rather than fatty acids with bends (oleic, linoleic, linolenic, ricinoleic).

The long stem of the Pop is the fatty acid and the candy sphere stuck onto one end of the stem is a sodium (Na) ion or a potassium (K) ion depending on whether you used NaOH or KOH to make the soap.

Let me talk a bit more about the Sodium version first --

If you stick Tootsie Roll Pops into a styrofoam ball to make a candy centerpiece, the stems point inward to the center. The candy ends face outward touch each other. This is roughly how soap crystals are constructed in a bar of soap -- they pack together so the sodium ions face out toward the watery liquid phase, and the fatty acids point inward toward any superfat or other fat-soluble materials.

Sodium ions are a bit fatter around than their fatty acid stem, but this tidy packing arrangement works pretty well for sodium soap molecules. They are quite happy to form solid-ish balls and plates and hotdogs and stay that way. As we use a bar of soap for bathing, these sodium soap molecules will only reluctantly let go of their neighbors to become fully liquid.

For soap molecules made with straight fatty acids, the jump from solid to liquid is fairly abrupt -- one moment there are soap crystals, and the next there is a watery, sudsy soap solution. To use another analogy, these soap molecules act a bit like bricks in a wall -- the bricks remain firmly together as long as the mortar lasts, but once the mortar fails, the bricks fall easily.






Source: http://danareneestyle.blogspot.com/2013/04/pinspired-candy-topiaries.html

If you could see sodium soap molecules made with lots of oleic acid or other bendy fatty acids, you would see a similar story, although the resulting "candy centerpiece" in a high-oleic soap is not nearly as tidy. The bends in oleic acid and similar fatty acids prevent the soap molecules from packing together as tidily and tightly as their straight chain cousins.

The solid-ish crystals in a high-oleic soap are not as "waterproof" as crystals in a low-oleic soap. When you wash with bar of high-oleic soap, the water penetrates quickly into the high-oleic crystals, and that causes the crystals to deform and slide past each other. The crystals haven't quite given up being crystals, but they are not able to stay rigidly fixed in place.

This liquid crystal stage is when we see that ropy oleic gel (or snot) we all love to hate. As more and more water is mixed into the soap, the liquid crystals (aka the oleic gel) gradually break down into a watery, sudsy soap solution. 

A high-oleic soap is more like a bowl of spaghetti with alfredo sauce. The strands of spaghetti are a tangled ball stuck together with the sauce. When you pick up a bite with a fork, the strands gradually untwine and pull apart.

Potassium soap molecules have the same general shapes as sodium soap molecules, except for one key difference -- the diameter of a potassium ion (the candy at the end of the fatty acid stick) is quite a bit larger than the diameter of a sodium ion, because the electrons of a Potassium ion are not held as tightly by the nucleus (the center) of the ion. Potassium is more like a big, soft marshmallow, and Sodium is more like hard candy.

The bulky Potassium ion prevents the soap molecules from packing as tightly and neatly together. This is true regardless of the fatty acids the Potassium ions are attached to. This interference allows water to penetrate more easily into the crystalline structure, so the soap molecules can more easily dissolve into the wash water. 

To go back to my analogies, potassium weakens the mortar of the brick wall (soap molecules made with straight fatty acids) and it makes the pasta (soap molecules with bent fatty acids) more slippery and slithery.

So in summary --

By adding a bit of KOH to a high lard (or palm or tallow) recipe, the fairly insoluble soap molecules created from stearic and palmitic acids will become more soluble in water. You'll get more lather quicker and with less work.

Adding a bit of KOH to a high-oleic soap will make the oleic gel not quite as strong. The gel will "snot" less and dissolve better into the wash water.

edited to clarify my explanation


----------



## Spice (Feb 26, 2018)

DeeAnna, your intelligence fascinates me!


----------



## dibbles (Feb 26, 2018)

Wow DeeAnna, great explanation. And with a visual aid too!


----------



## Meena (Jan 5, 2019)

DeeAnna said:


> 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 --



I want to echo the thanks of others for your work on this amazing treatise!  I just LOVE long explanations, the longer the better!  I appreciate a mind like yours.   

You are right, I thought soap was "a dry solid."  What an eye-opening read this was!  Super helpful - thanks a lot!


----------



## Hendejm (Jan 5, 2019)

I know this is an older thread but I firmly believe this should be required reading for all new soapers (me included). Thanks to DeeAnna and all other contributors!


----------



## DeeAnna (Jan 5, 2019)

I'm still around and willing to answer questions. Please feel free to keep this thread alive and ask your questions here.

In fact, re-reading this thread reminds me of stuff I've shared and have since forgotten.  There was a thread started recently where the OP asked (paraphrasing here) why potassium soaps were more soluble in water than sodium soaps. I don't exactly remember the entire context of the question, but I think maybe Post 90 in this thread would have been a good one to share with the OP.


----------



## melinda48 (Jan 5, 2019)

This was a fascinating thread. I agree wholeheartedly, even though it is an older thread, all us newbies should read this!


----------



## Steve85569 (Jan 5, 2019)

A sticky version of this would be great (hint for the Admins).

Thanks again to DeeAnna for the chemistry and time spent on this and other posts.


----------



## penelopejane (Jan 6, 2019)

earlene said:


> I have made only a few batches of 95% NaOH with 5% KOH bar soap, so take my response with a grain of salt.  No, it doesn't in such a low percentage.  In a higher percentage it does, but that is also dependent on your recipe.  As you can surmise, soaps with a higher percentage of hard oils would be less affected, whereas soaps with a higher percentage of soft oils would be more affected.
> 
> I tend to use more soft oils in most of my recipes and noticed a significant difference when I tried a 10% KOH/90% NaOH in softness of the resulting soap.  I expect a long cure will solve the problem eventually, but haven't looked back at those particular soaps in a while, so don't yet know.  I can only hope.



I have found that anything above KOH 5% makes a noticeably softer soap and a long cure (18 months plus) does not help at all.


----------



## DeeAnna (Jan 6, 2019)

Yes, softness from KOH will be a permanent thing. I've left my KOH shave soap in the open air for months. It dries out and becomes more crumbly, but still remains soft.


----------



## paragon (Jan 22, 2020)

@DeeAnna You wrote on your site that soap becomes milder after a lengthy cure, and everyone is telling me the same thing in another thread, but nobody seems to know why. Is this related to the changes in crystal/liquid phases which you described earlier, or is it another phenomenon?


----------

