chemistry question!

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JBot

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I saw this video ([ame]https://www.youtube.com/watch?v=tTQ_YU8aNWY&feature=youtu.be[/ame]) posted in a FB group, and she talks about adding a sugar syrup to the soap at the end of the HP cook to make the soap more fluid. She refers to the syrup (2 parts sugar, one part water) as a "solvent."

What I'm wondering is whether adding a lot of sugar -- based on what she says in the video, her sugar must be 10-14% PPO -- would increase the solubility of the soap and make it dissolve faster and/or not last as long.

I've heard that sugar increases bubbles. So does coconut oil, and it's my understanding that coconut oil increases solubility, so I've been thinking that no matter what's creating the bubbles, more bubbles = higher solubility = soap doesn't last as long. Am I on the right track here?
 

IrishLass

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Wow- that's a lot of sugar ppo. For what it's worth, I used 10% sugar in a batch once and it left my soap so soft that it remained dent-able for over a year. And the overall texture of the bar was quite spongy/rubbery. After about 2 years, the soap felt 'normal' enough to me, so I finally used a bar and the bubblage was awesome- much like a 100% CO soap even though it was one of my regular formulas with only 28% CO, but there's no way I would ever use so much sugar again. Two years is a long time to wait for a soap. lol

My normal amount of sugar is 5% (about 2 tbsp. ppo), which is the highest I'll go.


IrishLass :)


Edited to add- wow- besides the huge amount of sugar, she then adds 2 oz. of glycerin to it after that. Yep, the soap is beautifully fluid and all that, but I'm very curious how long it takes to cure out and how it ends up feeling on the skin (sticky perhaps?). She didn't show an after cure picture or mention anything about how the texture of the soap feels, etc... Those are the things that are most important to me, rather than fluidity.
 
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JBot

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I completely agree about texture vs. fluidity. Fluidity is purely cosmetic, but I'm always tweaking things here and there to see if I can improve on the cosmetics without sacrificing quality of formula, texture, etc.

I definitely wasn't planning on going as far as the glycerin, and the additional water at the end makes me nervous too. I actually don't like to go below 30% lye concentration, even in my HP.

I might try 10% PPO sugar just to see how it comes out. I've been using 5%, and I don't notice that the bars are any softer, but I guess I haven't been watching for that either.

Anybody know why sugar would make the soap softer?
 

kchaystack

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Probably the extra water in the syrup. If she used 28% or 25% solution, and then added all that syrup... that is alot of water.
 

DeeAnna

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Sugar interferes with the crystallization process that naturally happens in bar soap as the soap cures. Because of this property, sugar is one of the "solvents" that can be used to make transparent soap. And this interference is the reason why sugar tends to make the soap softer and lather more freely.
 

TwystedPryncess

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And with all that water, if she is coloring with TD, will it come out with glycerin rivers? Sometimes that's a really cool look on purpose, sometimes notsomuch. Then there is the addition of glycerin, which I would have no idea what it would do in terms of glycerin rivers, because my chemistry isn't that great.
 

JBot

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Sugar interferes with the crystallization process that naturally happens in bar soap as the soap cures. Because of this property, sugar is one of the "solvents" that can be used to make transparent soap. And this interference is the reason why sugar tends to make the soap softer and lather more freely.
Where can I learn more about this crystallization process? I think it might be a factor in why my HP starts to look misshapen as it cures, but I don't know much about how the crystallization works or why this is happening. I've been able to reduce the warping quite a bit, but I've only had two batches that didn't warp at all. I've tested every factor that I've been able to identify from the batches that never got misshapen, and I still haven't solved it. (This is all independent of the questions about the sugar.)
 

DeeAnna

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"... I think it might be a factor in why my HP starts to look misshapen as it cures..."

It's far, far more likely that this problem comes from simple water evaporation. You typically use more water with HP than with CP and when that water evaporates out, an HP bar shrinks more than a CP bar. That loss of volume is going to cause more distortion of the shape. "Shrunken head syndrome" -- where the top of the bar shrinks down in the middle -- is the usual outcome unless you mound the center of the soap higher than the sides.

"...And with all that water, if she is coloring with TD, will it come out with glycerin rivers?..."

No, I don't think so. This is a hot process soap. Streaking and mottling (aka glycerin rivers, although it's not glycerin at all!) is something you are mainly going to see only in CP soap. In CP soap, you pour the batter into the mold when saponification is actively going on and the soap is heating up to its gel temperature. The soap particles are able to form as the soap just sits quietly in the mold -- and then the soap goes into gel, again in a quiet environment.

In HP soap, the saponification is done by the time you mold the soap, you've been actively stirring the soap and adding stuff to it, and you put the soap into the mold at or below the soap's gel temperature. There's almost no chance you are going to get streaking or mottling under those conditions.
 
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JBot

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"... I think it might be a factor in why my HP starts to look misshapen as it cures..."

It's far, far more likely that this problem comes from simple water evaporation. You typically use more water with HP than with CP and when that water evaporates out, an HP bar shrinks more than a CP bar. That loss of volume is going to cause more distortion of the shape. "Shrunken head syndrome" -- where the top of the bar shrinks down in the middle -- is the usual outcome unless you mound the center of the soap higher than the sides.
I actually do my HP using a 30-33% lye solution, which isn't as concentrated as water discounted CP, but it's not 25-27% either. I've noticed that more water does result in the bar being more misshapen, so I think water is a big part of it, but not all of it.

Instead of the bar shrinking down in the middle (my adjustments have eliminated that), they get kind of ripply or wavy-looking along the sides/edges (not the faces).

When I make the exact same recipe using CP, with the exact same amount of water, I don't get the ripply edges. So why does the evaporation of identical amounts of water lead to rippling in HP, but not CP? I've been thinking it has something to do with the way the water is distributed through the soap matrix, which might be related to the way it crystalizes.

Interestingly, a lot of the HP-ers in this FB group use far more water than I do, and they claim they don't get any shrinking/rippling/warping etc. I'm not sure what they know that I don't, or whether they're telling the truth. Nobody there had any ideas for me (I did try). I asked once for people to post pictures of cured bars, since most of my rippling happens between 2-6 weeks. I think maybe two people posted pictures, which is interesting, since they post LOTS of freshly-cut pictures.

I know quite a few people on there are selling them 1-2 weeks after making them, so maybe the bars are long gone by the time the shrinking sets in. Or maybe I'm just cynical.
 

IrishLass

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IInterestingly, a lot of the HP-ers in this FB group use far more water than I do, and they claim they don't get any shrinking/rippling/warping etc. I'm not sure what they know that I don't, or whether they're telling the truth. Nobody there had any ideas for me (I did try). I asked once for people to post pictures of cured bars, since most of my rippling happens between 2-6 weeks. I think maybe two people posted pictures, which is interesting, since they post LOTS of freshly-cut pictures.

I know quite a few people on there are selling them 1-2 weeks after making them, so maybe the bars are long gone by the time the shrinking sets in. Or maybe I'm just cynical.
Color me cynical, too. I don't have an FB account, so I don't belong to any FB groups, but I've read plenty on the different forums about the super high-water HP craze making the rounds on the said groups, and you're not alone in the experience that you described in the above quote. Although there are tons of pics of freshly-cut soaps using this method, all the posts/threads that I've run across written by those who keep up with the FB groups report that it's like pulling teeth to get anyone that's touting this method to post any 4 to 6-week post-cure pics. Instead, they are greeted with the deafening sound of crickets.

I'm truly surprised you were actually able to run across as many as 2 people who posted pics of their cured bars, but the huge dearth of after-pics makes me wonder if they are really and truly post-cure pics, and if so- how many weeks old were they?

I truly hate to sound so cynical, but if this method is really the awesome, cutting-edge, bees knees that it's touted to be, why aren't people falling over themselves to post 4 to 6-week after-cure pics as proof of it's awesomeness? Goodness- it would be the first thing I would do.

Instead, the fact that many are all selling these bars 1 to 2 weeks after making them without a clue as to how they look after 4 to 6 weeks because they haven't been properly time-tested, speaks volumes to me, and not in a good way.

Sorry, Jbot, didn't mean to go on a rant. I wish I had an answer to your ripple conundrum, but I have no idea. Hopefully DeeAnna might be able to shed some light on it.


IrishLass :)
 

DeeAnna

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"... So why does the evaporation of identical amounts of water lead to rippling in HP, but not CP?..."

Thanks for explaining how you do HP. I've been basing my answers on how HP is typically done by soapers who have explained their method here on SMF and how I've handled the few HP soap batches I've made. Your technique is a little different, so it makes sense that you are seeing different things happening as your HP soap cures.

As I mentioned before, HP soap is usually stirred a lot while it is saponifying and then it is put into a mold when it is fairly cool so it doesn't remain undisturbed and in a gel state for long, if at all. What I think is happening is the different types of soap molecules (short chain soap molecules vs. long chain ones) respond to all this disturbance by creating different types of crystalline structures compared with how the same soap molecules would organize in a CP soap.

And that different structure as well as any extra water is most likely why HP may deform more while curing.
 
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Dharlee

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Is rebatching and HP sort of considered the same basically? I mean in terms of the final result? I do know the difference of one starting out as CP either bought for rebatch purposes or a CP soap you're trying to save, etc, but is the end result basically the same?

The reason I ask is that there is a famous person who says that the soap is ready to use in days after this is done. No wonder people get confused. Since cominh here I have learned not to believe every single thing I see or read and not to depend on that person to know everything...
 

The Efficacious Gentleman

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It depends on your definition of "ready" - it would be safe to use it, of course, but even if the source soap is fully cured, it would still need to dry out again and restructure itself after being broken down like that.

As I would consider a soap "ready" it would not be.
 

DeeAnna

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"...Is rebatching and HP sort of considered the same basically? ..."

I'd say in a general sense, yes, they're kind of the same. I would be comfortable saying they are more similar to each other in how they're processed than either one is to CP soap.
 

Dharlee

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So much to learn! I am constantly amazed at the knowledge shared here!
 

JBot

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I'm truly surprised you were actually able to run across as many as 2 people who posted pics of their cured bars, but the huge dearth of after-pics makes me wonder if they are really and truly post-cure pics, and if so- how many weeks old were they?

Sorry, Jbot, didn't mean to go on a rant. I wish I had an answer to your ripple conundrum, but I have no idea. Hopefully DeeAnna might be able to shed some light on it.
Well, since I'm in agreement with pretty much everything you said, the rant doesn't bother me in the least! One of the pictures was "a couple" weeks old, according to the poster. Since they generally look fine for the first 2 weeks, that wasn't very meaningful. Another one was supposedly a "couple months" old, but it looked exactly like all the fresh pictures she posted, so I wondered if it was a picture of a soap that WAS older, but the photo was taken when it was fresh. Who knows.

Thanks for explaining how you do HP. . .Your technique is a little different, so it makes sense that you are seeing different things happening as your HP soap cures.
I have been seeing pretty much the same type of rippling thing with both of the HP methods I've tried; it's the degree of rippling that varies. I used to make it in the oven, but lately I've been doing the "Sharon Johnson stick blend" method, where I get the oils hot, don't let the lye water cool down, and stick blend continuously for several minutes. Then I zap test and put in my fragrance, colors, etc. It goes really fast, I get a more fluid batter, and there's less rippling in the finished bars.

This is pure speculation, but I think this method helps cut back on rippling because the batter saponifies more evenly. When I was using the oven, the soap would sit undisturbed and gel from the outside in, which meant the outside was probably over-cooked by the time the inside was done. I would stir it up when it was finished, but maybe that just wasn't enough to even things out. I did try stirring it periodically during the process, but that actually made things worse.

Besides using less water, the other things that seem to help reduce rippling are unmolding sooner and letting the unmolded log sit for a day or two before cutting. I don't really know why those things help. I'm also wondering whether faster (or slower) cooling of the soap after it's in the mold might make a difference. What do you think?

My mold doesn't fit in my freezer, unfortunately, so I can't try that.

As I mentioned before, HP soap is usually stirred a lot while it is saponifying and then it is put into a mold when it is fairly cool so it doesn't remain undisturbed and in a gel state for long, if at all. What I think is happening is the different types of soap molecules (short chain soap molecules vs. long chain ones) respond to all this disturbance by creating different types of crystalline structures compared with how the same soap molecules would organize in a CP soap.
That's getting into the territory that I had in mind when I first asked about crystallization! Now I'm wondering: is this something I can manipulate? You mentioned soap sitting undisturbed in a gel state. If that helps the organization of the crystals, then what about re-gelling, so to speak? Like making the soap, putting it in the mold, then putting it in the oven at 170 for an hour or so? (This was actually suggested to me by topofmurrayhill, but I haven't tested it yet.)

"...Is rebatching and HP sort of considered the same basically? ..."

I'd say in a general sense, yes, they're kind of the same. I would be comfortable saying they are more similar to each other in how they're processed than either one is to CP soap.
Not sure I agree with that. Other than the application of heat and molding after saponification instead of before/during, do HP and rebatch really have that much in common? CP and HP are both made up "fresh," combining oils and lye water; none of that is involved in rebatch. You can also get a fairly homogenized texture with HP that I think is closer to CP than rebatch. I've never seen a rebatch that didn't have visible chunks here and there. The way I look at it, HP is just CP that's being taken a step further prior to going in the mold. Rebatch is more like taking finished soap and going backwards.

I tried adding the sugar syrup after the cook in yesterday's batch. I wasn't comfortable using the 10-14% recommended in the video, so I went with my usual 5%, but instead of putting it all in the water before adding the lye, I split it in half. Half went in the water up front, and half was added as a warm syrup after the cook. It DID make the batter more fluid. Not as fluid as in the video -- she used more water, more sugar, and also glycerin -- but definitely enough to be noticeable.

The downside: it's one more thing to juggle during the process, and it made the batter rather sticky, which was problematic when I was trying to pour and swirl. So the stickiness might cancel out the increased fluidity.

The stickiness went away as the soap cooled and hardened. It does not seem softer than usual, probably because I used my standard amount of sugar. The logs actually seem harder than usual now that they've cooled.

Do you think that strictly in terms of the affect on lather, it makes a difference whether the sugar is added up front or at the end?
 

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