# CP Soap Curing time Speed up Possible??



## Sahil Doshi (Apr 24, 2018)

Hey all!

I was once reading an article about a lady who mistakenly put her fresh batch of CP Soap in her microwave oven and 'cooked' her soap in the preheated oven and apparently was able to wave off 3-4 weeks of curing time.

This got me thinking about the benefits of curing of the soap naturally:

*Allows water to evaporate so that bar becomes harder:* Now, evaporation of water depends on the following factors namely: relative humidity, temperature of soap, temperature of surrounding, speed of air flowing through. Now, for example, I have a set of 8 soaps spaced out without them touching on one of those cake cooling racks and I have a hair dryer blowing towards the soaps from the 4 directions. Here, we know for sure that the air will be a lot more warmer and the speed of the hot air is also quite high and the relative humidity is low since I have hair dryers blowing out hot air.

*Reduction of pH:* Now, pH is basically the amount of H+ ions in any material. I did my research and there is a direct correlation between the temperature of a material and its pH. What I figured from it was that as temperature increases, the pH goes down. So, the same hair dryer example as above will also fit to reduce the pH.
*Makes the bar more milder: *When the pH of the soap will go down, automatically the soap will be a lot more milder and a lot more softer on the skin.

So, potentially, it is possible to mechanically reduce the curing time of CP soaps by putting them in some sort of dryer. Maybe a bigger sized version of a toaster maybe??? A lot more lower temperature, maybe something around 40C - 50C. With internal fans for air movement

What do you'll think of this? Do you'll think its possible??


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## lsg (Apr 24, 2018)

Water evaporation does not mean a soap is cured.  As a soap cures, it gets milder and longer-lasting.  You can use sodium lactate, stearic acid or even salt in the lye water to make a harder bar, but that doesn't mean it will last or is a mild bar.  I have never heard of anyone mistaking a microwave for a regular oven.


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## The Efficacious Gentleman (Apr 24, 2018)

My favourite example in this is a Castile bar. At 1 month it has probably lost most of the water which it will lose. At 3 months there won't be massive changes in the water amount going forward. And yet the difference between a 1 month or a 3 month bar when compared to a 12 month old bar is "yuge". 

Why? 

It can't be down to water loss. At these points, the soap will have its pH and that is pretty much that. Time won't play a big factor in it. 

So what is it?

Soap is never really solid. Even a bar that can be used as a hammer is not physically speaking a real solid. It has a crystalline structure which forms over time which has potentially far more impact on the performance of the bar than anything else. 

That is not sped up by quick drying in any way. In fact, I wonder if force drying a bar might well hinder the long term crystalline structure formation to an extent that a bar left to its own devices would be better at 3 months than a bar which had been "speed cured". Would be an interesting experiment


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## DeeAnna (Apr 24, 2018)

Yes, pH is affected by temperature, but it's a two way street. What did your research tell you about what happens to pH when the temperature drops? Also, just how much of a pH drop do you expect to get from your plans?


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## dixiedragon (Apr 24, 2018)

I don't know of a way to speed the crystalline structure and I would think that is something you'd need a lab to examine. I have been playing around a bit with "twice baked soap" - and I've been wondering what would happen with repeated bakings?

I do think that cold tends to slow everything down - for example, I think freezing soap slows the cure - so I would suggest a warm, dry room (use a dehumidifier, perhaps) with good circulation would be a good first step towards speeding up cure.


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## Sahil Doshi (Apr 24, 2018)

This was actually my mistake. What I meant was an oven.



DeeAnna said:


> Yes, pH is affected by temperature, but it's a two way street. What did your research tell you about what happens to pH when the temperature drops? Also, just how much of a pH drop do you expect to get from your plans?



In case the temperature reduces, it makes the pH increase. Also, in case of pure water, the pH recorded at 0C was 6.14 and the pH recorded at 100C was 7.47


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## DeeAnna (Apr 24, 2018)

The implication in your original post is that the pH would be permanently reduced. I wanted to make sure you didn't think that was really going to happen. 

Remember too that water is not a buffer nor is it a salt. Soap is both. So you cannot assume what happens with water also happens with soap.


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## Sahil Doshi (Apr 24, 2018)

DeeAnna said:


> The implication in your original post is that the pH would be permanently reduced. I wanted to make sure you didn't think that was really going to happen.
> 
> Remember too that water is not a buffer nor is it a salt. Soap is both. So you cannot assume what happens with water also happens with soap.



Quite True.. Thats an interesting point..


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## Barmaid (Apr 24, 2018)

I believe what you are referring to is CPOP soap, soap that is cooked in the oven. A hot processed soap. Hot process soaps often cure a bit faster than cold in my experience.  If you are looking for ways to speed up curing, that is, at least the water evaporation part, I would suggest simply starting with less water (by using a water discount, don't go too crazy if using hot process) and keep good notes weekly on weight (I mark one bar from each batch and weigh it weekly until it no longer changes, usually about 4-5 weeks, I usually lose .05-.1 oz from each bar per week) so that you can get a good understanding of how much water you are losing from each bar. When you make soap again, you can start with a bit less water each time. After the cook and cut all you can do is be patient, supply really good air flow and run a dehumidifier.  
I think if you run hot air over them all of the time, you could end up with some minor problems, like DOS. I do not know that for sure, but it is something that came to mind when you said that.....so if you do try it, I would love to know, good results or bad!


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## Kari (Apr 24, 2018)

lsg said:


> Water evaporation does not mean a soap is cured.  As a soap cures, it gets milder and longer-lasting.  You can use sodium lactate, stearic acid or even salt in the lye water to make a harder bar, but that doesn't mean it will last or is a mild bar.  I have never heard of anyone mistaking a microwave for a regular oven.



huh, I was under the impression that the saponification process happens fairly quickly, and that your cold process bars are 'safe' to use after a couple of days. (this is why hot process is considered faster, since you're using heat to speed up the saponification) Curing is intended to make the bars harder and longer lasting - which is a result of water evaporation.

Does cure mean something else outside water evaporation?


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## dixiedragon (Apr 24, 2018)

Kari said:


> huh, I was under the impression that the saponification process happens fairly quickly, and that your cold process bars are 'safe' to use after a couple of days. (this is why hot process is considered faster, since you're using heat to speed up the saponification) Curing is intended to make the bars harder and longer lasting - which is a result of water evaporation.
> 
> Does cure mean something else outside water evaporation?



Yes, it's more than just evaporation.
https://classicbells.com/soap/cure.html

IMO, 1-day old HP soap is a bit milder than 1 day old CP. However, both still need at least 6 weeks. If it were just about water evaporation, then people would be soaping with the lowest possible amount of water in order to speed cure. Cold process is "safe" to use as soon as it doesn't zap, but safe doesn't mean pleasant. Wash your hands with some week-old soap - CP or HP - and then compare to some 8 week old soap.


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## cmzaha (Apr 24, 2018)

Kari said:


> huh, I was under the impression that the saponification process happens fairly quickly, and that your cold process bars are 'safe' to use after a couple of days. (this is why hot process is considered faster, since you're using heat to speed up the saponification) Curing is intended to make the bars harder and longer lasting - which is a result of water evaporation.
> 
> Does cure mean something else outside water evaporation?


Here is a great place to start reading about cure written by our own DeeAnna the chemist  Oops Dixidragon was faster than me with the info


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## jcandleattic (Apr 24, 2018)

To me the original post is mistaking "cure" with "saponification" which happens all the time. Once there is no active lye remaining in the soap, is has fully saponified. It will still need a full 4-6 week cure. Two completely different terms in soapmaking to mean completely different things. It's a common mistake.


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## Kari (Apr 24, 2018)

A lot of this seems to do with the types of oils used. Lard takes longer to trace, and olive oil is slow to trace - both are used as examples of soap that get distinctly better with age. That makes sense since this is all chemical reactions and if you change up the ingredients, your reaction will change as well.

I am curious if anyone had actually tried to speed up the cure.. and if it were possible to speed it up - if you would end up with a bar whose quality is equal to that of a bar left to sit for 8 weeks or more. The one challenge I can imagine is having a control.. since in order to get an apt comparison you'd need to still let the one bar sit for the full number of weeks.


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## cmzaha (Apr 24, 2018)

^^^It is pretty easy to save a bar from each batch then use another to test at least once a month. Sometimes one has to do their own testing to believe what others know


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## Lin19687 (Apr 24, 2018)

Someone asked me if they could put it in a Dehydrator ..


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## jcandleattic (Apr 24, 2018)

Kari said:


> I am curious if anyone had actually tried to speed up the cure.. and if it were possible to speed it up


This is an age old question, and the answer IMO always circles back to - no, there is no way to speed up cure time. 
Curing is more than just one single thing, and requires time. It's water evaporation along with a distinct chemical change occurring within the soap, and it's that chemical change that requires the time. 
If it was simply about water/liquid evaporation, then a 50/50 lye solution soap could be cured within a matter of days, but it is so much more than that.



Lin19687 said:


> Someone asked me if they could put it in a Dehydrator ..


That's because many people think curing is simply liquid evaporation. But it's so much more than that...


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## dixiedragon (Apr 24, 2018)

Actually, putting it in a dehydrator could make sense. I doubt it would speed up the crystallization, but if you live in a humid climate it would definitely help speed up the evaporation process. And I would think (just guessing here) that dryer soap would be less prone to DOS?


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## jcandleattic (Apr 24, 2018)

dixiedragon said:


> Actually, putting it in a dehydrator could make sense. I doubt it would speed up the crystallization, but if you live in a humid climate it would definitely help speed up the evaporation process. And I would think (just guessing here) that dryer soap would be less prone to DOS?


In almost every case of hearing about people doing this it "ruined" the soap. AKA melted it, warped it, made it drippy and sticky. 
I've never once heard a success story about putting soap in a dehydrator. 

But, I have no first hand knowledge so can only relate what I've read/heard from others.


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## cmzaha (Apr 24, 2018)

dixiedragon said:


> Actually, putting it in a dehydrator could make sense. I doubt it would speed up the crystallization, but if you live in a humid climate it would definitely help speed up the evaporation process. And I would think (just guessing here) that dryer soap would be less prone to DOS?


Most if not all dehydrators use heat and it will melt the soap. I tried this when I first starting soaping and my dehydrator goes low in heat but it still melted the soap or at least softened it severely. Mine goes as low as 95º F


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## dixiedragon (Apr 24, 2018)

I didn't know they got that warm! Interesting!


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## cmzaha (Apr 24, 2018)

My dehydrator is an Excalibur I do not remember how warm or cool some of the less expensive dehydrators get


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## Lin19687 (Apr 25, 2018)

I have a Cheap round one for Jerky, it gets hot.  Not ripping hot but hot.
i wouldn't waste my dehydrator for soap,  jerky is so much more tastier 

Jealous @cmzaha that is a Very Nice machine !


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## dixiedragon (Apr 25, 2018)

So I wonder, how does (say) Dial do it? While I don't think Dial is nearly as good as my soap, it doesn't give my hands the same feel as new-uncured soap does. It's drying but not irritating. So is Dial curing soap for 4+ weeks in ginormous warehouses?


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## BrewerGeorge (Apr 25, 2018)

I think it definitely IS possible to speed up cure; it's just that the process isn't possible for us handmade artisans.  The makers of Ivory and Dial aren't maintaining massive warehouses of curing soap bars, and they're ready to use immediately so they MUST be using something to accelerate the cure.

But they're cooking soap and extruding it, milling it a few times, probably exposing it to CO2 and controlled humidity/temps of precise calibration, then making bar shapes via hydraulic press and large pressure.

Traditional methods have no way to emulate that.  But as I said in another thread recently, there is no real reason to speed cure.  Just make soap more often and build a stock so you always have properly aged soap to use.


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## DeeAnna (Apr 25, 2018)

What BG said ^^^

Commercial soap is chipped or flaked into small pieces, vacuum dried to the desired water content, and then kneaded and mixed until it has the desired structure. It can be milled to compact it and further develop the desired structure before being pressed into bars, but most is just extruded or pressed into the desired bar shape straight off the mixer.

(FWIW, hand crafted soap makers often confuse milling with rebatching, but they are not at all the same thing.)

Other aspects of commercial soap is that a lot of it has very low to no superfat nor glycerin and many brands also have syndets blended in. These also affect the characteristics of the soap.


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## Dean (Apr 25, 2018)

dixiedragon said:


> So I wonder, how does (say) Dial do it? While I don't think Dial is nearly as good as my soap, it doesn't give my hands the same feel as new-uncured soap does. It's drying but not irritating. So is Dial curing soap for 4+ weeks in ginormous warehouses?



I was researching commercial soap yesterday.  Apparently most soap is made in Asia in the form of noodles and then sold to soap manufactures all over the world that mix in fragrance, color and whatever additives, compress, extrude, cut and stamp it into bars.  Interestingly the vegetable based noodle is usually just saponified coconut/palm 20/80.  Apparently the "crystalline" aspect of curing isn't an issue because by the time the product makes it to the consumer, enough time has passed, especially if you consider shipping and storing of the noodles prior to processing into bars. 

I requested a tour of local natural soap manufacturer's factory and was told they don't offer tours.  I bet anything the soap is made from Asian noodles...and not the delicious kind.


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## amd (Apr 25, 2018)

I just Googled the ingredients for Dial. I noticed they used "Coconut Acid* · Palm Acid* · Palm Kernel Acid* · Tallow Acid* *contains one or more of these". I believe the use of acids would saponify quicker, but because they don't have triglycerides they wouldn't produce glycerin. Here is where I enter a bit of speculation... the lack of glycerin (or reduced glycerin because they do still use other oils), would possibly allow crystal structure to reassemble faster after the milling/extruding/pressing... ? Again, total speculation on my part.


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## DeeAnna (Apr 25, 2018)

The crystal structure is determined by the milling/extruding/pressing. That's one of the main points of all that manipulation.


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## Dean (Apr 25, 2018)

DeeAnna said:


> The crystal structure is determined by the milling/extruding/pressing. That's one of the main points of all that manipulation.



Interesting.  Is that why some soap is "triple-milled"?


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## dixiedragon (Apr 25, 2018)

BrewerGeorge said:


> Traditional methods have no way to emulate that.  But as I said in another thread recently, there is no real reason to speed cure.  Just make soap more often and build a stock so you always have properly aged soap to use.



Make more soap is the answer to most problems, isn't it? 

So the milling extruding process speeds up the crystallization? We're guessing?



Dean said:


> I requested a tour of local natural soap manufacturer's factory and was told they don't offer tours.  I bet anything the soap is made from Asian noodles...and not the delicious kind.



To be fair, they may not be allowed to have tours b/c of insurance. The Golden Flake potato chip company in my area used to do all kinds of field trips, tours, etc. It was one of the most fun field trips we did during school - lots of samples! But they had to discontinue it for liability purposes.


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## DeeAnna (Apr 25, 2018)

Dean said:


> Interesting.  Is that why some soap is "triple-milled"?



Milling happens when soap is rolled between a pair of chilled steel or stone rollers. If you've seen clothes go through the wringer of an old washing machine or  if you've used a pasta machine to roll out noodle dough thinner and thinner ... that's milling.

Milling compresses the soap making it denser and longer lasting. Milling is also used to mix scent and color into soap. Because the soap is kept cool and dry during milling (compare that to rebatching!), this is a good way to preserve the aroma of expensive fragrances and delicate color. Everyday soap is not usually milled.

Triple milled means the soap has gone through a machine that has 3 sets of chilled steel or stone rollers. Or gone through one set of rollers a total of 3 times.



dixiedragon said:


> So the milling extruding process speeds up the crystallization? We're guessing?



Yes, the drying, mixing, and other manipulation of the soap alters the crystal structure of the soap. That's not a guess -- soap chemists actually measure the different types of crystal structures, know the properties created by the different types, and do their best to tailor the soap production process to make the kind of product they want.

The resulting crystal structure in commercial soap is not necessarily the same as what we get. For example -- Have you ever used a bar of commercial soap and had it crack (usually) on the short ends of the bar? That's related to the specific crystal structures within that bar. With handcrafted soap, that kind of cracking seldom happens, or if it does, the cracks occur pretty much randomly.


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## Dean (Apr 25, 2018)

dixiedragon said:


> To be fair, they may not be allowed to have tours b/c of insurance. The Golden Flake potato chip company in my area used to do all kinds of field trips, tours, etc. It was one of the most fun field trips we did during school - lots of samples! But they had to discontinue it for liability purposes.



I originally thought they didn't do tours because of the lye danger but now I'm pretty sure there is no lye on site due to the industry standard of using noodles.  Agree about liability though.  Having the public in a manufacturing area of any kind is a huge liability issue.  Toured Ben and Jerry's last year.  The public is kept completely separate from the manufacturing.  Basically we just saw the factory from a balcony and then ate a sample.  Kinda boring.



DeeAnna said:


> ...chemists actually measure the different types of crystal structures, know the properties created by the different types, and do their best to tailor the soap production process to make the kind of product they want...



Interesting.  I wondered if there is a way to  test crystallization.  So apparently there is...if you're a chemist.  It be awesome if someone could build a calculator that estimates when the crystallizing is complete based on fatty acids, water amount, area/season (humidity), etc.


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## Sahil Doshi (Apr 28, 2018)

That means that probably not with a dehydrator, but something that can speeden up the evaporation process may help with the curing?


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## jcandleattic (Apr 28, 2018)

Sahil Doshi said:


> That means that probably not with a dehydrator, but something that can speeden up the evaporation process may help with the curing?


No, that's a common but false assumption. All evaporation does is just that, evaporate the liquids. Curing is a chemical change within the soap structure itself, and nothing but time can make that happen.


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## DCM5150 (Apr 21, 2022)

Sahil Doshi said:


> This was actually my mistake. What I meant was an oven.
> 
> 
> 
> In case the temperature reduces, it makes the pH increase. Also, in case of pure water, the pH recorded at 0C was 6.14 and the pH recorded at 100C was 7.47



I think you got the temp/pH backwards. pH of water at 100C should be 6.14 and 7.47 @0C.

And to be clear, (pure) water is still neutral at a pH of 6.14 and 7.47 at those temps. Changing the pH by changing temperature doesn't affect how basic the soap is. When we talk about pH=7 as neutral, that is assuming 25C (77F) which is considered "room temp" or standard temp in many sciences


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## Relle (Apr 21, 2022)

DCM5150 said:


> I think you got the temp/pH backwards. pH of water at 100C should be 6.14 and 7.47 @0C.
> 
> And to be clear, (pure) water is still neutral at a pH of 6.14 and 7.47 at those temps. Changing the pH by changing temperature doesn't affect how basic the soap is. When we talk about pH=7 as neutral, that is assuming 25C (77F) which is considered "room temp" or standard temp in many sciences


FYI, this thread is over 4yrs old, and the person you quoted hasn't been  in here since then, so is not likely to see your post.


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## Steve85569 (Apr 21, 2022)

Soap and wine finish their respected chemical reactions fairly quickly.
Both are better aged properly.
While their are some methods for speeding both in my humble opinion they do not produce a product with the same character and the traditional hand crafting methods. That is the whole point of small wineries and home crafted soaps is it not?


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## Zany_in_CO (Apr 21, 2022)

I once made a CP soap that needed to be shipped at the end of the week. I soaped one day, cut the next, _oven_ _rebatched_ it the next day. Did that one more time... double-rebatched soap. Turned out quite nice and ready to use by the time it reached its destination the next week.


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## DCM5150 (Apr 21, 2022)

Relle said:


> FYI, this thread is over 4yrs old, and the person you quoted hasn't been  in here since then, so is not likely to see your post.


I saw that and then realized I was reading the thread so others might be looking here too, so I posted anyway.


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