Recipes - Cold Process vs Hot Process

[Carl]

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!

 

[steffamarie]

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.

 

[Relle]

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.

 

[SaltedFig]

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!

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.

 

[IrishLass]

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

 

[Zany_in_CO]

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

PS: It's all good!

 

[xmasdeer]

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

 

[shunt2011]

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.

 

[DeeAnna]

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.

 

[earlene]

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.

 

[xmasdeer]

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

 

[Dean]

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.

 

[dixiedragon]

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.

 

[Candybee]

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.

 

[Dawni]

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..

 

[Carl]

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.

 

[DeeAnna]

"...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.

 

[xmasdeer]

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.

 

[Carl]

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.

 

[Dean]

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.