# Salt bar formula



## hoegarden (Mar 11, 2013)

[ame]http://www.youtube.com/watch?v=SVaK5sm0jmc[/ame]

I am trying for the first time to incorporate sea salt into my soap bar... The formula under soaping 101 mention to use 75% of salt based on total weight of oil.

Can I just confirm that 75% is really okay? Will it cause the soap to dry and cracky, or easily crush?


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## LuvOurNewf (Mar 11, 2013)

My typical salt bar recipe is, 90% coconut, 10% shea, 70% salt based on weight of oils used and superfatted to 20%.

After 4-6 week cure, the lather is outstanding and the feeling after using is great.
I do use individual molds to cut down on crumblies.


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## jcandleattic (Mar 11, 2013)

Yes, 75% salt per weight of oils is fine. Many people use up to 100% with no problems while others use as little as 25%. It all boils down to personal preference and personal experience. 
If you are not using individual molds however, just beware that they will be ready to cut in a couple hours or sooner. Most people who use a high percentage cut while still warm, otherwise they will be too hard to cut. 

Good luck.


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## Genny (Mar 11, 2013)

I use 100% table salt in mine & don't have any problems with cracking or crushiness.  They are hard as a rock.


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## hoegarden (Mar 11, 2013)

Is there any difference between using coarse salt and fine salt? Will the salt be melted under the high temperature?

Is there any difference in using normal table salt and the sea salt?

Can we add the salt during rebatching?


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## Seifenblasen (Mar 11, 2013)

hoegarden said:


> Is there any difference between using coarse salt and fine salt? Will the salt be melted under the high temperature?
> 
> Is there any difference in using normal table salt and the sea salt?
> 
> Can we add the salt during rebatching?



My personal preference is stick to medium/fine grained salts.  Tried using very course grained salt once and the bars came out very scratchy and crumbly when being cut.  No, the salt did not melt even though I CPOP the soap.

Both normal table salt and sea salt are fine.

I don't see why you cannot add salt during re-batching, but it seems like a lot of work as it is much easier to add the salt at trace instead of making it a two-step process.


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## Badger (Mar 12, 2013)

I was looking through this thread and it made me wonder if the rules for oils and size of your pan is the same for a salt bar or does that formula (length x depth x width x .40) change due to salt content?


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## Seifenblasen (Mar 12, 2013)

Not sure where you got that formula and what units you use, I tend to do my own calculations using metric units.  

The density of NaOH is about 2.1g per cm3 and most soap making oils is about 0.9g per cm3.  The bulk density of salt is approximately 1.2g per cm3 and the density of salt crystal is about 2.2g per cm3 (there are a lot of air spaces between the grains, hence the bulk density is much lower).   Since the oil will fill some of the air spaces between the salt grains, but not quite as well as air, I am making up my own "density of salt in soap" of 1.7g per cm3 using the average of 1.2g per cm3 and 2.2g per cm3.  My calculations would then be:

weight of water + weight of NaOH/2.1 + weight of oils/0.9 + weight of salt/1.7 = total volume in cm3

I did not factor in additives such as pigments, essential/fragrance oils, etc. because they constitute a very small percentage of the soap.  My silly made-up "density of salt in soap" factor has enough error to accommodate those additives.


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## Badger (Mar 12, 2013)

The formula is for determining ho9w much oil to use in your mold and the formula was done in inches and ounces and could be found at this link.... http://www.soapmakingforum.com/f11/how-figure-how-much-oil-mold-2909/

I just wasn't sure if the amount of oils stays the same or if it changed due to the salt?


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## Seifenblasen (Mar 12, 2013)

_*I just wasn't sure if the amount of oils stays the same or if it changed due to the salt?*_

The amount of oils stays the same because you need the same amount of oil to react with the lye.  The salt is just an additive.  

Most salt bars contain 60% - 100% coconut oil because coconut oil has the ability to lather up even in salt water.  But because coconut oil is also very cleansing/drying, most people superfat salt bars at a much higher rate than regular soap.

Thanks for the link on calculating oil/mold!  Most of the time, however, I prefer to do it my way!  :twisted:  (After, it is just simple math).


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## Badger (Mar 12, 2013)

Yep, you do what works for you   For some people, Math is not so simple, hehehe!  Thank you for your answer and sorry if it seemed a bit silly


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## hoegarden (Mar 12, 2013)

I don't get the maths at all...

Do you think adding sugar will help in lathering if we are to decrease the CO? Since there are various threads saying on adding sugar in CP soap.. will the sugar n salt clash?


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## melstan775 (Mar 12, 2013)

I get it the quesiton, Badger, but not the answer given. Salt is an additive, and therefore you are adding mass to your soap recipe. So how do you adjust for how much space your recipe will take up after you add the salt.  Good question, but I don't understand the answer.


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## Seifenblasen (Mar 12, 2013)

Seifenblasen said:


> weight of water + weight of NaOH/2.1 + weight of oils/0.9 + weight of salt/1.7 = total volume in cm3
> 
> I did not factor in additives such as pigments, essential/fragrance oils, etc. because they constitute a very small percentage of the soap.  My silly made-up "density of salt in soap" factor has enough error to accommodate those additives.



Badger, I was afraid you might feel insulted if I simplify it too much.  I also had trouble putting brackets and getting all the math symbols in the equation.  So let's try this with an example.  If I am making a batch with 1000g oils, 300g water, 160g lye, and 750g salt:

   300g + 160g/2.1 + 1000g/0.9 + 750g/1.7
= 300 + 76.19 + 1111.11 + 441.18   
= 1928.48

I would need a mold about 1928 cm3 in size, or 118 cubic inches.


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## Seifenblasen (Mar 12, 2013)

hoegarden said:


> I don't get the maths at all...
> 
> Do you think adding sugar will help in lathering if we are to decrease the CO? Since there are various threads saying on adding sugar in CP soap.. will the sugar n salt clash?



It is nothing more than a calculation of volume using the weight and density of a few ingredients.

As to sugar, I seriously doubt it will help.  The reason coconut oil is used is because other oils don't lather well (or at all) in salt water.  Sugar boost the lather under normal circumstances, but if the oils are not lathering, there is nothing to boost ...


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## new12soap (Mar 12, 2013)

I believe the question is not how large a mold to use, but what size batch to make to fit the mold you have. In very general terms, LxWxH of the mold (in inches) x .40 = ounces of oil for a batch to fill that particular mold. Since I am adding salt to make a salt bar, how do I calculate what size batch I need to make plus account for the volume of salt to fill _this mold._


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## Seifenblasen (Mar 12, 2013)

Easy.  Just flip the equation backwards.

The calculations from the example used before showed that for 1000g oil and 750g salt, a mold the size of slightly less than 2000 cm3 is needed.  Therefore we can assume the "ratio of mold to oil" is approximately 2:1. 

So if you have a mold that is 16" x 4" x 3.5" = 224 inches3 = 3670 cm3, you need 3670/2 = 1835g of oil, or 1835g/28 = 65.5 oz. of oil.


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## Bama (Mar 13, 2013)

I like this recipe and it is already superfatted at 20%. It works well and I just put it in the summerbeemeadow soap calc and resize it to fit whatever mold I am using.
http://thesoapbar.blogspot.com/2008/07/salt-soap-tutorial-by-ladybug-soapworks.html#


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## cerelife (Mar 13, 2013)

Badger, I get you! I've got a couple of degrees (one is in physics) but for the life of me, I can't do the "simple" math for soap molds...I start reading and then my brain goes all "LaLaLa...not going there, don't even bother"...thank goodness the DH gets it and makes all of my log molds!
BUT, I may be able to help you out. I usually make 2lb batches of regular soap so I have several of that size log mold. I only have three 2lb "salt soap" log molds, but I wanted to make 4 batches recently. I upped my salt soap recipe to 3lbs for the last batch and it fit perfectly into two 2lb regular molds. BTW, I use table salt at 80% of my oils.
Hope this helps!


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