# How to use stearic acid in CP soap?



## mikvahnrose (Sep 15, 2016)

I read you use 5% of stearic acid to your batch of soap. 

Is that 5% ppo, or 5% of the entire recipe? (lye/oils/water?)

Is 5% even correct? Because i made a recipe with it (i think i used to much) and it traced up almost instantly. 

I am very confused by this. I want my soap to be harder but i think im going about this the wrong way


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## kchaystack (Sep 15, 2016)

Um, this is a bad idea.  

Stearic acid will saponify instantly, accelerating your batch.  

Try adding a teaspoon of table salt per pound of oil to your water and dissolving it before you add your lye.  

You can also get some sodium lactate and add it at 3% of your oil rate to your lye water. 

You can also change your recipe to use more palm, lard, tallow or butters.  (tho more butters can reduce lather)


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## Soapmaker145 (Sep 15, 2016)

I've used it in recipes when I wanted to adjust ratios of various fatty acids.  I've never used more then 5%.  It works fine as long as you know what to expect.

Stearic acid will react instantly and it will look like you have trace but it's false trace. The rest of the oils haven't had a chance to react yet. You need to stir for a while longer until you are sure you reached stable trace.  Since  stearic acid forms soap, it helps emulsify the oils and lye and speeds up trace a little.  Also, you need to work at a higher temperature to avoid stearic spots in the soap. 

I like to add it to a mostly hazelnut soap that I make for a friend that takes forever and a day to trace. As far as hard soap, time cures all.  Alternatively, you can add 5 to 10% Mango or shea butters.  They'll add the stearic acid to the soap batter and help harden soap better than anything else I tried.


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## mikvahnrose (Sep 15, 2016)

Does salt behave the same way the stearic acid would to make a harder bar of soap?

I bought about 1/2 lb worth of stearic acid and would like to figure out how to use it at least. What is recommended usage of stearic acid to ppo?

I upped my solid oils (palm and coconut) to almost 55% as total yield. But i hear that is too high? I do not like soft slimy bars of soap. This is what the soapcalc determined my recipe to be.

Hardness: 48
Cleansing: 20
Conditioning: 49
Bubbly: 24
Creamy: 31
Iodine: 50
INS: 163


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## kchaystack (Sep 15, 2016)

Well, you can make shaving soap, or use it to thicken lotions. 

I would not go over 35 - 40 percent palm, and I do not like more than 15 - 20 percent coconut.  

As for those numbers...  they do not mean what common sense tells us they mean.  Salt does harden your bars, but not for the same reason stearic acid does.  

How long are you curing your bars?   You might not be curing them long enough. 

What is your full recipe?  including water and NaOH amounts?  If you use the water as % of oils setting instead of a lye concentration setting, it can lead to soft bars that need to cure longer.

How do you store your soap between uses?  It needs to be in a soap dish that allows it to completely dry between uses, and no sit in any water what so ever.


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## Susie (Sep 15, 2016)

mikvahnrose said:


> Is that 5% ppo, or 5% of the entire recipe? (lye/oils/water?)



That would be 5% of the total amount of oils.  For example:

Lard 60%
Olive Oil 15%
Coconut Oil 15%
Castor Oil 5%
Stearic Acid 5%

Now, having said that, just because you CAN use it in a recipe, that does not mean you SHOULD use it in a recipe.  

I have never used it, so I have no opinions about it.  I was just answering the question.


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## IrishLass (Sep 15, 2016)

Stearic acid can be quite tricky to use in CP, but it can be done if you keep the % of stearic on the low side and soap on the hotter side, as Soapmaker145 pointed out. I used it @ 3% ppo once in a CP batch, but I much prefer using cocoa butter or mango butter in my formulas to increase hardness in my soap instead, because they bring with them other nice qualities to my soap that straight stearic acid doesn't.

Having said that, though, I do regularly use 28% stearic acid ppo in soap, but only in my shaving soap which I make via HP, and I can say without a doubt that it's so much easier to work with in HP as opposed to CP. 

You may want to consider HPing with it instead.


IrishLass


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## mikvahnrose (Sep 15, 2016)

Im very new to this (5 batches of soap) so i really don't know exactly what water as % of oils mean tbh.

I have been using brambleberry and started out using measurement in oz rather than percentages.

I just make the batch of lye water for whatever it tells me to for the amount of oils i am using at the time at superfat levels of 5%. I don't even know how to measure a master batch of lye (to use for everything) or consider water discount. That is probably easier than i am making it out to be

This is my first time i am doing percentages.


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## kchaystack (Sep 15, 2016)

I just went to look at the new BB calculator.  

I really do not like it.  It defaults to 38% Water as percent of oils, or about a 28% lye concentration.  So that could be why your soap is soft.

Again, your recipe would really help us figure out what's going on.

There are many posts on the forum that explain why this is not the best way to go.

I would strongly suggest reading the thread on soapcalc, and following the tutorial also in the forum on how to use it.  Also changing the default lye setting to concentration and using about 30%.


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## lenarenee (Sep 15, 2016)

mikvahnrose said:


> Does salt behave the same way the stearic acid would to make a harder bar of soap?
> 
> I bought about 1/2 lb worth of stearic acid and would like to figure out how to use it at least. What is recommended usage of stearic acid to ppo?
> 
> ...



I love stearic acid in lotions and lotion bars. In fact, I won't use beeswax any more, I find the stearic more  soothing, plus easier to use than beeswax.


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## Obsidian (Sep 15, 2016)

with a hardness if 48, it shouldn't be a soft slimey bar. How long are you curing it before use and does it get a chance to completely dry between uses? No matter the recipe, if handmade soap can't dry thoroughly, it will get soft.


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## mikvahnrose (Sep 15, 2016)

The hardness of 48 is a totally new recipe and i wanted to try out something with stearic acid to harden the soap. I usually cure it for 5 weeks. 

I use 
30% coconut
25% palm 
25% olive
15% shea butter
4% castor
.5% stearic 
.5% E.O 

Before i had the 
Coconut: 25 
Palm: 25
Olive:30 

But it ended up making the bar not the way i like it. Idk i'm just playing around and finding what i like. I LOVE bubbles. I need my bubbles. To me bubbles is king haha. So i want to do whatever to get my bubbles. Sounds childish yes...but BUBBLES. xD


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## The Efficacious Gentleman (Sep 16, 2016)

Try make making this - 

Palm 40%
Olive 35%
Coconut 20%
Castor 5%

Before you add the sodium hydroxide to the water, dissolve some sugar in to the water at a rate of 3% sugar compared to the oil weight. So if you are using 500g of oils in total, the sugar should be 5% of 500g. 

This will boos the bubbles a great deal, but it will also make the soap hotter as it saponifies so if you usually insulate your soap you will need less - exactly how much will be some trial and error. 

Susie is another bubble-lover and she uses lower coconut with no issues at all


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## Susie (Sep 16, 2016)

Indeed!  I use Coconut oil 15%, Castor oil 5%, and sugar or honey in every batch.  I have to have my bubbles!

If you are unopposed to using animal fats, you can try this:

Tallow 30%
Lard 35%
Olive Oil 15%
Coconut Oil 15%
Castor Oil 5%
Sugar or honey 5-10 g PPO

I find my honey tends to overheat soap far more than sugar does.  

I subtract 1 oz of water from the total amount the recipe calls for, and use that as hot water to dissolve that sugar.  I add that sugar water to the oils before the lye water. 

In this recipe, the tallow tends to give big bubbles and hardness, where the lard gives dense, creamy lather.  It is the best of both worlds lather wise.  I add the sugar or honey for more bubbles and the castor oil to help those bubbles stay around longer.


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## IrishLass (Sep 16, 2016)

mikvahnrose said:


> The hardness of 48 is a totally new recipe and i wanted to try out something with stearic acid to harden the soap. I usually cure it for 5 weeks.
> 
> I use
> 30% coconut
> ...


 
Susie is not the only bubble-lover around here.  I gotta have my bubbles, too- as do my hubby and son (they're bubble-lovers as well). 

Depending on the formula, my normal amounts of coconut oil and/or pko run between 28% to 31.5% (other than the formula I make using 100% coconut oil with a 20% superfat). Most (but not all) around here consider those percentages pretty high, but they are what work for me.

Besides the higher amounts of CO/PKO, I also use 5% sugar ppo, and .5% tetrasodium EDTA per the weight of my whole batch. We have very hard water, you see (which diminishes bubbly lather), and so all these things help tremendously to combat that. 

Edited to add: For what it's worth, my 5% amount of sugar ppo (roughly 2 tablespoons ppo) does not make my soap heat up at all. Honey will heat it up for me, but not regular table sugar.


IrishLass


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## mx5inpenn (Sep 16, 2016)

I use a high lard recipe with 5% castor and 15% coconut. With 1tsp ppo of sugar added, after a 3 month cure, this makes a very hard bar with enough bubbles to keep my 2 and 4 year olds happy.


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## Susie (Sep 16, 2016)

IrishLass said:


> Susie is not the only bubble-lover around here.  I gotta have my bubbles, too- as do my hubby and son (they're bubble-lovers as well).
> 
> Depending on the formula, my normal amounts of coconut oil and/or pko run between 28% to 31.5% (other than the formula I make using 100% coconut oil with a 20% superfat). Most (but not all) around here consider those percentages pretty high, but they are what work for me.
> 
> ...



I have soft water, which makes the tetrasodium EDTA, extra sugar, and extra CO unnecessary.  I am very glad I am not the only person that has experienced the overheating of honey.  It makes for lovely lather, but I have to watch it like a hawk.


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## BrewerGeorge (Sep 16, 2016)

mikvahnrose said:


> Does salt behave the same way the stearic acid would to make a harder bar of soap?
> 
> I bought about 1/2 lb worth of stearic acid and would like to figure out how to use it at least. What is recommended usage of stearic acid to ppo?
> 
> ...


That should not be a slimy bar.  Forty-eight is a respectable hardness.  I suspect it just needs to cure longer - especially if you used BB's default water amount.

As for stearic, I use it in my basic body bar at 1%.  I probably don't _need_ it, but like you I bought it so I'm using it albeit slowly.


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## cmzaha (Sep 16, 2016)

I use the same amount of sugar as IL with no overheating problems, but Honey heats up with considerably with less used, 2 tbs in my 60 oz oils and it heats up


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## FNG (Sep 16, 2016)

As others have mentioned, there are a multitude of other ways to get a harder bar aside from using SA.  However, if you do choose to use SA in any amount, I have found it easier to work with in CP and HP settings by following a few recommendations:

1) Don't skimp on the water (or water replacement) in your lye solution as the extra fluidity helps you mix the SA in.  You may need to cure longer or let the soap sit in the mold a bit longer depending on your oils and water % used overall.

2) Blend all of your other oils with the lye solution and add the SA last.  It will still stiffen up immediately but I find it's easier to blend in this way, even with high SA% shaving soaps. It has a melting point of 156.7 degrees F so make sure you keep it around this temp before trying to add it.  

3) Soap at a higher temp, as mentioned by and for reasons mentioned by others already.

4) If you plan on using lower flash point Essential/Fragrance oils, be ready to stir by hand like mad as your stick blender is going to be useless at lower temps if you have enough SA in your soap to cause the batter to seize due to insta-saponification when added.


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## topofmurrayhill (Sep 16, 2016)

FNG said:


> 4) If you plan on using lower flash point Essential/Fragrance oils, be ready to stir by hand like mad as your stick blender is going to be useless at lower temps if you have enough SA in your soap to cause the batter to seize due to insta-saponification when added.



The flash point of your fragrance is not at all relevant to the temperature you can soap at. The flash point is used by your supplier so they know how the fragrance can be shipped. It's of no practical use to a soapmaker or candlemaker.


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## FNG (Sep 16, 2016)

topofmurrayhill said:


> The flash point of your fragrance is not at all relevant to the temperature you can soap at. The flash point is used by your supplier so they know how the fragrance can be shipped. It's of no practical use to a soapmaker or candlemaker.



If you soap at too high of a temp you risk evaporating those expensive oils.  For example, when I make a high SA% shave soap I bring in the SA while it's still fluid at around 150-ish degrees.  Let's say I want to add Bergamot EO (flash point @ 122F), I wait until the batter has cooled a bit before adding it to ensure the EO does not evaporate.  At the very least I combine the SA with the other oils so I'm not dropping a 122F flash point EO on 150-ish oil.  This makes the batter a bit harder to stir at this point.

It's a little extra elbow grease, but I think it's worth it to ensure I can get the most out of my low flash point EOs.  Maybe you don't think this is necessary but I feel it helps after testing this out a few times.

EDIT:  I guess I should also clarify that while the flash point denotes the point at which an EO becomes flammable, it is because it is evaporating and therefore easy to light with an open flame.  It won't burn off when the soap saponifies and raises in temp as it should be already incorporated thoroughly at this point.  However, if you drop a low FP EO on a hot bit of oil or soap batter some of it could evaporate off.

You can test this on your own and note you'll get a huge whiff of whatever you dropped in as it evaporates and permeates the air.  Then mix a batch that is closer to the FP (I feel like 10-12 degrees is as far as I like to be off) and test the difference.


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## topofmurrayhill (Sep 16, 2016)

FNG said:


> If you soap at too high of a temp you risk evaporating those expensive oils.  For example, when I make a high SA% shave soap I bring in the SA while it's still fluid at around 150-ish degrees.  Let's say I want to add Bergamot EO (flash point @ 122F), I wait until the batter has cooled a bit before adding it to ensure the EO does not evaporate.  At the very least I combine the SA with the other oils so I'm not dropping a 122F flash point EO on 150-ish oil.  This makes the batter a bit harder to stir at this point.
> 
> It's a little extra elbow grease, but I think it's worth it to ensure I can get the most out of my low flash point EOs.  Maybe you don't think this is necessary but I feel it helps after testing this out a few times.
> 
> ...



You can't infer anything useful from the flash point in the context of crafting. I've been hearing the same misconceptions for 10 years and witnessed many attempt to clarify it, but I'm sure the "burning off" idea will continue forever.

Flash point is a number that is derived from a standardized procedure to test flammability, but nothing special happens at that temperature except under the conditions of that test.

You are suggesting that flash point is directly related to vapor pressure -- the rate of evaporation -- but it is also related to how much vapor there needs to be for ignition to occur. Liquid A can evaporate more slowly than liquid B but have a lower flash point because it's simply more flammable and less vapor needs to be in the air above the surface.

Under the circumstances of soaping, evaporation is not significantly going to affect fragrance based on the volatility of one fragrance versus another -- especially when it's mixed into something else at 6% concentration. There's not enough evaporation to make a difference.

Temps are much higher in candlemaking, but people have not noticed any correlation with fragrance loss. Many of the same FOs are used, typical flash points are similar, and similar concentrations are used in wax as in oil. Candle mistakes are sometimes remelted to 180 F and poured again -- a torture test under which people have found that the fragrance is not significantly affected.


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## FNG (Sep 17, 2016)

topofmurrayhill said:


> You can't infer anything useful from the flash point in the context of crafting. I've been hearing the same misconceptions for 10 years and witnessed many attempt to clarify it, but I'm sure the "burning off" idea will continue forever.
> 
> Flash point is a number that is derived from a standardized procedure to test flammability, but nothing special happens at that temperature except under the conditions of that test.
> 
> ...



While we may agree to disagree, I think a more valid test of your candle example would be to see what happens when pure EO hits that 180F surface.  Not while it's in a solution of candle wax already.  As I mentioned, once it's in the soap and blended up it's not really a concern.  The example you give doesn't seem to match what I've stated. Perhaps it is inconsequential if you're able to get it mixed in quickly enough, but this is difficult to do with SA in play.  Remember, I didn't recommend this for any and all CP recipes :mrgreen:

I've personally tested this a few times to see the difference, particularly with SA since it has a higher melting point and I tend to work with 40-60% recipes for shaving frequently.  Might be perception bias but I feel my methodology to correct this (whether necessary or not) is worth the possibility. To me the fact that it's vaporizing at all and significantly notable in the olfactory impact (sudden increase of EO scent) at higher temps pushes me to err on the side of caution.


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## mikvahnrose (Sep 22, 2016)

The Efficacious Gentleman said:


> Try make making this -
> 
> Palm 40%
> Olive 35%
> ...



That recipe does look pretty good, i would love to give it a go! But, I love shea butter soap, so what would be a good percentage of shea butter to use to replace some of the other oils, would this change the super fat percentage if at all? I just tested out my most recent soap after a week of cure time (not enough time i know) but i feel that it is too drying. The amount of bubbles that resulted was spot on though :]


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## The Efficacious Gentleman (Sep 22, 2016)

mikvahnrose said:


> That recipe does look pretty good, i would love to give it a go! But, I love shea butter soap, so what would be a good percentage of shea butter to use to replace some of the other oils, would this change the super fat percentage if at all? I just tested out my most recent soap after a week of cure time (not enough time i know) but i feel that it is too drying. The amount of bubbles that resulted was spot on though :]



Maybe take 10% from the palm for shea.  Although I would also make it as is so that you can compare - many people can't tell the difference between 10% shea in a soap or that 10% being in lard.  Palm is similar, but in a side-by-side comparison I am not too sure.


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## kchaystack (Sep 22, 2016)

I agree with Effy,  take 5 - 10% from your Palm and move it to shea.  Remember too much shea can inhibit lather.


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## mikvahnrose (Sep 22, 2016)

Yeah, that is exactly what i was thinking. Taking some away from the palm and using 8 percent shea.


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## JeanmarieT (Apr 26, 2022)

mikvahnrose said:


> I read you use 5% of stearic acid to your batch of soap.
> 
> Is that 5% ppo, or 5% of the entire recipe? (lye/oils/water?)
> 
> ...


All the guidelines I've read say to start with 0.5% or your oil weight, not 5%!!


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## Relle (Apr 26, 2022)

JeanmarieT said:


> All the guidelines I've read say to start with 0.5% or your oil weight, not 5%!!


This person hasn't been here for 3 yrs, so not likely to see your quoted post to them. This post is from 2016.


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## JeanmarieT (Apr 27, 2022)

Relle said:


> This person hasn't been here for 3 yrs, so not likely to see your quoted post to them. This post is from 2016.


Thanks for your concern.


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## Lia chalid (Jun 21, 2022)

FNG said:


> As others have mentioned, there are a multitude of other ways to get a harder bar aside from using SA.  However, if you do choose to use SA in any amount, I have found it easier to work with in CP and HP settings by following a few recommendations:
> 
> 1) Don't skimp on the water (or water replacement) in your lye solution as the extra fluidity helps you mix the SA in.  You may need to cure longer or let the soap sit in the mold a bit longer depending on your oils and water % used overall.
> 
> ...


I'm a newbie,
How I can add the SA on the last part? I melt the SA first or just add it powdery like that?

I've just add the SA powder at the oils and it couldn't mix and make the soap have so many white dots.

I really want to make a hard bar but I want it to be moisture enough to skin...
Can you tell me how to make it??


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## earlene (Jun 21, 2022)

When I used stearic acid, I melted it with the soft oils, just like I do for any other hard oil.  The melting point of stearic acid is 69.3°C  (156.7°F).  The heat transfer method won't melt it, so it has to pre-melted, and I find that some hard oils (including Stearic Acid) melt more uniformly with the surrounding warmer liquid oils to maintain the heat all around the surface of the harder oils as they float within the mixture.


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## Gingerbread2 (Sep 24, 2022)

Susie said:


> That would be 5% of the total amount of oils.  For example:
> 
> Lard 60%
> Olive Oil 15%
> ...


I am using 5% of my oils as stearic acid in one of my basic recipes but I used the soap calc to calculate the results.  I have being doing it for a few months and I am not having trouble with acceleration any more than I would with other some FO etc.  I do find it really important to melt that stearic acid really well with other hard oils blending very well while it is hot and then add the other oils while they are hot.  THEN I let my oils cool.  It does start to thicken quickly but using the stick blender I just keep it moving long enough to make sure it is a very evenly mix.  I have time to blend colours and make design but I don't waste time either.  So far I am happy with the results.


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