# Recipes - Cold Process vs Hot Process



## Carl (Oct 22, 2018)

Hi,
My 1st of many posts here!
I made my 1st batch of Cold Process over the weekend.  

I noticed there are a lot of soap recipes on the web, but a lot of them do not specify to use cold process or hot process.

So can I take any soap recipe and use it either way, hot process or cold process, or should certain ones be for cold only and others for hot only?

Thanks ahead of time!


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## steffamarie (Oct 22, 2018)

A lot of people develop different recipes for HP vs CP, and a lot of it has to do with superfatting. By doing a superfat after the cook in HP, you have a greater chance of having the skin benefits of whatever oil you SF with. In CP, the SF doesn't matter - the lye monster gobbles up whichever molecules it wants with no regard for the expensive oils you might want to have left over.

In general, I believe you can take pretty much any recipe and do it either way. I could be wrong as I do not HP, but I'm sure some HPers will correct me if this is the case!

ETA: Soap is a wash-off product, and the chance of retaining skin benefits of expensive oils in either process rather than in a leave-on product like lotion or body butter is pretty low, so if you're wanting to SF after cook with something fancy like argan oil, it's probably best to use it for a product that isn't being immediately rinsed off.


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## Relle (Oct 22, 2018)

Hi Carl

Welcome, would you like to go into the Introduction forum and tell us a bit about yourself and how you got into soaping.


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## SaltedFig (Oct 22, 2018)

Carl said:


> Hi,
> My 1st of many posts here!
> I made my 1st batch of Cold Process over the weekend.
> 
> ...



The same recipe can be used for both CP and HP soaps. Adding heat speeds up the chemical reaction, but you will get soap from any properly formulated recipe, providing your batter has reached emulsion before you ceased participating in the process 

The thing that is most often different between the two (CP and HP) is the water content. Generally, a lye concentration of 30 to 33% is good for CP, and a slightly lower lye concentration is use for HP (adding water, to account for evaporation). How much extra water you would need depends on how open your vessel is during the cook, and how hot/quickly you cook the soap, but generally a lye concentration of around 28% to 30% is fairly good for a lidded crockpot cook.

The most important thing you can do with any of these recipes is to run them through a soap calculator. Always check your hydroxide amount for the recipe, to ensure you are making a safe soap.


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## IrishLass (Oct 22, 2018)

Welcome Carl!

I've made many batches of both CP and HP, and you'll be happy to know that CP and HP recipes are completely interchangeable. Whichever one you use for CP, you can use for HP, but just add more water if making it via HP, as Salted Fig said .

In regards to superfat and HP- when all is said and done over time and cure, you still might not end up with the super-fatting oil you added after the cook as your exclusive superfat in your HP. Maybe in the short term you might, but soap is not static. It changes over time at the chemical level as it tries to maintain an equilibrium.


IrishLass


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## Zany_in_CO (Oct 22, 2018)

I prefer the smooth texture of CP because HP tends to have a more "rustic" appearance. 

PS: It's all good!


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## xmasdeer (Nov 8, 2018)

Can someone kindly explain the reason why some people HP instead of CP. What are the benefits of HP.


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## shunt2011 (Nov 8, 2018)

xmasdeer said:


> Can someone kindly explain the reason why some people HP instead of CP. What are the benefits of HP.



There's really very little difference.  HP requires more water/liquid to keep it from drying out.  You can technically add the SF of your choice after the cook and EO/FO's have a tendency to do a bit better in HP when added after the cook and cooled a bit.  The finish is much more rustic looking and harder to do swirls etc.

CP is smoother, EO/FO may or may not alter a bit due to the active lye, can use a water discount and easier to do swirls and other techniques.  

They both require a good cure contrary to those who will say that HP doesn't need the same cure.  

It's a personal choice pretty much.  I've seen beautiful HP and CP.  I've done both, prefer CP.


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## DeeAnna (Nov 8, 2018)

Speaking in general terms -- In hot process, the soap is saponified first and then is put in the mold. In cold process, the soap is poured into the mold first and then it saponifies.

HP soap is fully saponified more quickly (in a few hours or less) because it's usually heated and cooked to accelerate saponification. It usually has a more rustic appearance because it's typically thick and gloppy when it's packed into the mold.

CP soap takes longer to saponify (maybe 1-3 days) because it's not cooked. CP soap batter is (usually) thinner when it's poured into the mold, so it's easier to do complicated designs.

Some people just prefer one method over the other. 

You might be able to use less scent in HP than in CP. I'm not sure I entirely agree with that, but I can see the logic. 

There is a myth that HP soap is ready to use a day or two after its made, but CP soap takes weeks to get to that point. Many "get rich quick" soapers fall for that myth so they can get soap on the shelves fast.

Some types of soap are far more easily made using a hot process method. Shave soap is one example because it is often made with fatty acids which saponify very fast. Some fragrances accelerate saponification to the point that it's really tough to use a CP method, so HP makes more sense.


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## earlene (Nov 8, 2018)

One caveat to the above discussion, is that some ingredients don't lend themselves well to CP soaping.

For example, two ingredients come to mind:  beeswax and stearic acid both have fairly high melting points, so using them in CP soap making can be a challenge.  Not to say it's impossible, but they tend to be used more often in the HP methods, as far as I have noticed.


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## xmasdeer (Nov 8, 2018)

Thanks for all your answers, the more I read on HP the more confused I was becoming. I might try a batch and see how I go but I really like playing with the swirls, so will likely keep on CP'ing


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## Dean (Nov 8, 2018)

I was experimenting in HP for awhile. 

Benefits that I found:

No ash. 
EO scent stronger .
No partial gel.
I also found that it made softer soap.  Didn't find SF after cook benefits.  After about 1/2 dozen batches, I've returned to CP.


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## dixiedragon (Nov 8, 2018)

I think HP is better if you want to make a soap with honey and beeswax. The honey and the beeswax add sugar to the soap, which makes it more prone to overheating. Plus if you are soaping with beeswax, you have to soap hotter so your beeswax doesn't solidify. While I have never had a honey beeswax batch overheat to the point of separation, volcano or tunnel, I do worry about it. HP eliminates that worry.

I also have a particular FO that I love that turns to the soap into mashed potatoes on a stick. The only way not to have very 'rustic' (aka lumpy and rough) soap with this FO is to HP it.


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## Candybee (Nov 8, 2018)

There is no one reason people prefer one method over the other. I CP the majority of my soaps because I can make soap quicker and because its easier to make detailed swirled and complex color combos.

I HP my soap when using difficult additives or FOs that don't work well with CP.  I also use HP for rebatching soaps that I want to save.

You don't need to use HP to superfat, you can do that with either process.

So using either method is a personal preference.


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## Dawni (Nov 9, 2018)

I'm very new to soaping and have very few of either CP or HP batches.

I like the rustic look of HP so I do mostly that. Although I also found that some things are really better off done by CP - my brine soaps come to mind. I tried both methods and the HP one was so stressful lol

And of course, like mentioned above, you can't really do the complicated swirls with HP its just too "thick" even if you can get it fluid. An experienced soaper might disagree though...

Also, for an excited newbie like me, I can test my crumbs and scrapings for bubbles much quicker in HP but that's a minor detail lol

The biggest draw of HP, at least for me, is the cleanup after haha.. I just need to soak my slow cooker and all utensils in water and just wash like how I'd wash dishes after some time. With CP it's been a pain to wash off the oily stuff..


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## Carl (Nov 9, 2018)

Now that I've been doing this for a few weeks, here is my experience so far:
Last weekend I tried a HP batch.  I've been showering with it all week, lol.  I understand that some say its not ready yet, but I think it has been working awesome.

The other things I've noticed is that HP will take more or your time.  Although CP takes more time before you can use the soap, it is actually taking less time of your labor.  You are not inputting labor while it is sitting on the shelf.


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## DeeAnna (Nov 9, 2018)

_"...CP takes more time before you can use the soap..."_

I don't share this point of view, @Carl. HP soap is not at its best any sooner than CP -- they take about the same time for a full cure to get the best quality soap. Sure, HP soap is fully saponified in a few hours vs. CP soap being fully saponified in a day or two, but after saponification is over, the soaps are pretty much on the same footing and need about the same time for cure. Some people cure their HP soap for a couple of weeks longer, in fact, because many people use more liquid in HP recipes and it takes longer for the soap to become as hard as the equivalent soap done with a CP method.

If  you want to use the soap right away, sure, there's nothing saying you can't use it. That's true for CP soap as much as HP soap, despite all the myths floating around about CP soap taking weeks to be safe to use. Realize, however, that _any _soap without a full cure is going to be softer, not lather as well, and not last as long. If that doesn't bother you, that's fine, but I'll be honest with you -- what you think is "awesome" soap right now is not nearly as awesome as what that soap will be in 4-6 weeks. Keep notes of the hardness, lather quality, and skin feel over time, and you'll see the difference for yourself.


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## xmasdeer (Nov 9, 2018)

Thanks for all these comments, it is really getting interesting with these many hints and tips in conversation.  Last Christmas I was given CP soap as a gift, it lasted 2 days, almost melted in the shower.  Last week we purchased soap in a little village, very expensive, and it lasted 4 days in the shower.  As far as I am concerned, these people have lost a customer by not curing their soap, now that I know the significance of curing.


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## Carl (Nov 9, 2018)

Good point.  I'll have to experiment more.  I made a HP bar last Saturday and started using it on Sunday.  It was very lathery and sudsy!  I shower twice a day and figure it has about 2 or 3 more showers in it.  This is typically about how long a bar that I get at a gift shop or craft show lasts me.



I will do more longevity comparison tests when my CP is cured.


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## Dean (Nov 9, 2018)

Carl said:


> Good point.  I'll have to experiment more.  I made a HP bar last Saturday and started using it on Sunday.  It was very lathery and sudsy!  I shower twice a day and figure it has about 2 or 3 more showers in it.  This is typically about how long a bar that I get at a gift shop or craft show lasts me.
> 
> 
> 
> I will do more longevity comparison tests when my CP is cured.



I went thru 2 bars a week of fully cured HP soap.


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## shunt2011 (Nov 9, 2018)

Carl said:


> Good point.  I'll have to experiment more.  I made a HP bar last Saturday and started using it on Sunday.  It was very lathery and sudsy!  I shower twice a day and figure it has about 2 or 3 more showers in it.  This is typically about how long a bar that I get at a gift shop or craft show lasts me.
> 
> 
> 
> I will do more longevity comparison tests when my CP is cured.



Then you've been ripped off.   My CP soap cured 4-6 weeks will last 3-4 weeks for my husband.  Just because you can use it doesn't mean you should.  HP sometimes requires a longer cure than CP due to the amount of liquid needed to keep it workable.  I can use my CP after a few days but don't.   There's more than just water leaving the soap with cure.  There are structural changes too I think that happen behind the scenes.  

Also, make sure you are keeping it well drained.


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## DeeAnna (Nov 9, 2018)

What Shari ^^^ said. The soap you fellows are using isn't fully cured or the recipe isn't designed for decent longevity or your soap bars are tiny. Or all of the above.

My husband is the type who rubs the bar of soap directly on his skin. Since he has a good pelt of body hair, that's tough on any bar of soap. I make pine tar soap for him alone to use, so I know exactly how fast he alone uses up this soap. A 4-5 ounce bar of his PT soap lasts him about 3 weeks with once-daily showers.


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## Carl (Nov 9, 2018)

OMG,  I've never had a bar of soap last me that long, LOL. 

But I do keep it on the soap dish in the shower.  Maybe I need to rethink where I store it between use.


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## DeeAnna (Nov 9, 2018)

Good point, @Carl. Yes, if your soap can't dry out between showers, it's also going to be quite soft and wear away quickly.


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## Dawni (Nov 9, 2018)

I agree with all that's been said above. 
I may be new to soap making but I've been using handmade soaps for ages now and I've never used one that only lasted days.
The good ones take my family weeks to finish.. And I remember there was one bar that took months. I keep trying to find that maker but maybe she's stopped making soap since.

I think, especially regarding HP, it's semantics? People not knowing the differences between can and should, or between safe and best... And it all just snowballed into myths.

I know I can use my scraps immediately after the cook, but I know I should use the rest of the bar only after 4-6 weeks.
Or my CP soap isn't safe right after pouring but it will be in a few days. But like HP it'll be best after some weeks.

When I was doing research before I started soaping, I did come across sites saying you can use HP soap right after. Well they're right. You can. But it doesn't mean you should, and some sites also say that...


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## xmasdeer (Nov 10, 2018)

There certainly is a difference in waiting 6 weeks for the soap to cure.  My 100% olive oil and 50/50 olive/sunflower oil soaps are really hard after 6 weeks, less oily on the skin and feel lovely on the skin, unlike the first tests days after batching and 2 weeks after batching. I personally think I will be letting all of my soaps sit 6 weeks or longer on the shelf before anyone uses them.


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## shunt2011 (Nov 10, 2018)

When I made 100% OO soap, it had to cure 12-18 months due to the slime factor.  I don’t make it anymore as I don’t like it. Makes my skin tight feeling. 

Many here make a batch a year. There are also others like me who just don’t like it.  If it works for you then go for it.


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## earlene (Nov 10, 2018)

Besides the process and the cure time, it's also the make-up of the bar (the formula), not to mention how the bar is cared for once in use, that affects how long it lasts in use.

Example:  100% CO soap melts fast in use because it draws water to itself, so it doesn't last as long as my other soaps.
The oils used in each soap affects how long lasting that bar of soap may be when in use.

Any soap that sits in water and stays wet between use, is going to melt faster than if it is allowed to dry out between uses.  I remove my bar of soap from the shower and allow it to dry on a soap tray that doesn't let the soap sit in pooled water.  My husband leaves his on the shower shelf sitting in water between uses.  If I left mine in the shower, it would get wet twice a day (or as often as the shower runs, were we a more-than-two-person family).

Whether HP or CP, formula and care of the soap in between use will really make a difference in how long the soap last.  But also I tend to cure my soap a lot longer than some.  I tend to keep it curing for months and now years.  As you make more soap, you will have the opportunity to use older soap with a longer cure and may find that it lasts even longer than you expected from your earlier experiments.  And with that longer cure, I have found that some soaps that were only so-so when supposedly sufficiently cured, are actually pretty darn good with an even longer cure.


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## amd (Nov 15, 2018)

xmasdeer said:


> Last Christmas I was given CP soap as a gift, it lasted 2 days, almost melted in the shower.  Last week we purchased soap in a little village, very expensive, and it lasted 4 days in the shower.  As far as I am concerned, these people have lost a customer by not curing their soap, now that I know the significance of curing.



It may not necessarily be a curing issue. I have found this problem a few times in my OPSS (other people's soap stash), where many of the soaps will hang out for YEARS after I purchase them before they get used. A soap I used recently had been purchased July 2017, it was a 5 oz bar and lasted about a week in the shower - my husband used it once and I used it until it was a sliver, the kids didn't like the smell so they didn't touch it (I asked because the soap used up so fast). The first ingredient: coconut oil. I suspect that the maker used a huge amount of it to get a hard cheap bar. I won't be buying from them again as their bars were $8 each - and are uncolored. I don't mind paying $8 for a pretty swirled bar of soap, but this one has a double whammy of not lasting very long and being plain.


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## ibct1969 (Nov 19, 2018)

xmasdeer said:


> Thanks for all these comments, it is really getting interesting with these many hints and tips in conversation.  Last Christmas I was given CP soap as a gift, it lasted 2 days, almost melted in the shower.  Last week we purchased soap in a little village, very expensive, and it lasted 4 days in the shower.  As far as I am concerned, these people have lost a customer by not curing their soap, now that I know the significance of curing.



Yes, for sure.  Curing is super important for a few reasons.  That is interesting though - about the melting bars.  I wonder - are you are using a soap dish that allows the CP soap to dry between your showers?   Our CP soap lasts for a a few weeks.


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## threewildoils (Nov 23, 2018)

Hi,
Some time ago I posted in IG my little experiment, showing the importance of proper curing period. Planning on making HP soap soon and curious how different results will be.


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## msunnerstood (Nov 23, 2018)

Dean said:


> I went thru 2 bars a week of fully cured HP soap.


I'll admit Im confused by this. I HP exclusively and just the end cut of my cured bars last in my shower for 3 weeks with 4 adults in the house. 

I am sure ingredients play a role in the longevity of the soap so maybe thats the difference?


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## xmasdeer (Dec 6, 2018)

I don't know why the soap melted in the shower, we always keep our soap on a dish that holes in it for drainage and is not near the water unless you pick it up. The soap that melted was a gift and it was soft to touch, so I am assuming that it was freshly made. I also have no idea what it was made of.  My own soap, even after a being freshly made, last longer than the gifted soap.


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