# Sugar and/or Salt to make a hard bar



## chloe (Feb 1, 2015)

I wanted to know if anyone has had experience using salt and/or sugar to make their soap harder. If so, what kind of sugar and salt? How much? Is it very different from or as hard as sodium lactate? Any other tips in making a hard bar? I saw in another thread this was briefly touched upon... But thought I'd try to get more details. Any tips would be helpful! Thank youuuu!


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## Lion Of Judah (Feb 1, 2015)

Salt is used to firm up your bar / harden , while sugar is used to boost lather. i have never used sodium lactate so i can not give you a comparative view of the two. salt can be used anywhere from 1teaspoon to 1 tablespoon ppo , too much salt can cut your lather down. i use regular sugar and coarse sea salt . mixed in with your "liquid" until properly dissolved then mix in your lye . i find that while some oil and butters may help to build a firm bar it is curing / the drying out process that helps as well . the longer a soap has to dry then the hardness improves.


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## Obsidian (Feb 1, 2015)

I personally like salt better to harden soap, I use 1 tsp PPO dissolved into the water before adding lye. I use whatever salt I have around, usually canning salt or sea salt.


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## IrishLass (Feb 2, 2015)

Sugar won't harden soap- actually, it will do the opposite if too much is used. I like to keep sugar to no more than 5% ppo in my batches, which is something like 2 tablespoons ppo. Anything more than that and my soap starts to lose some of its hardness. Like Lion of Judah said, though, it will help to boost your lather. I use it at 5% in pretty much all my formulas except for my 100% CO soap with 20% superfat.

Salt, on the other hand will harden soap, but it also will impede lather if you add too much, although there are ways that you can get around that by tweaking your bubbly oils and superfat. It's all a balancing act.

Sodium lactate helps to both harden soap _and_ to enhance lather, although I wouldn't say that it increases bubbles. It's more like it gives the lather already present some extra 'body' or 'oomph' for lack of a better term. I use it in practically all my formulas at 3% ppo and I love it.


IrishLass


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## cmzaha (Feb 2, 2015)

IrishLass said:


> Sugar won't harden soap- actually, it will do the opposite if too much is used. I like to keep sugar to no more than 5% ppo in my batches, which is something like 2 tablespoons ppo. Anything more than that and my soap starts to lose some of its hardness. Like Lion of Judah said, though, it will help to boost your lather. I use it at 5% in pretty much all my formulas except for my 100% CO soap with 20% superfat.
> 
> Salt, on the other hand will harden soap, but it also will impede lather if you add too much, although there are ways that you can get around that by tweaking your bubbly oils and superfat. It's all a balancing act.
> 
> ...


I have made a sugar bar using 60% sugars (25% demerara sugar & 35% white granulated). It was amazing to me that they did not sweat excessively and stayed scrubbier than a salt bar. It was also a hard bar


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## The Efficacious Gentleman (Feb 2, 2015)

Interesting.

Was that sugar dissolved, or used more like salt in a salt bar?  Was it not sticky on the skin?


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## cmzaha (Feb 2, 2015)

Nope was not sticky on the skin and I did not dissolve the sugar, used it like salt in a salt bar. The one I can say that will positively not work is a sugar and salt bar. They do not set up well and sweat like you're in a rain forest. My sugar bars did not sweat badly and we had a very humid summer, they were made in March of last year


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## DeeAnna (Feb 2, 2015)

Some thoughts -- bar hardness-like-a-rock and bar longevity can be two entirely different properties -- both strongly depend on the fats in your recipe and to a lesser extent the amount of water and superfat. And hardness is specifically hardness at unmolding, not so much hardness after cure, so that's something to be clear about when setting goals for your soap.

Often tweaking the fat blend can make a big difference in these properties and (IMO) it's far better to refining the base recipe first, then mess with additives second. If you'd like a critique of your recipe, please share a recipe with all ingredients and weights.


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## IrishLass (Feb 2, 2015)

cmzaha said:


> Nope was not sticky on the skin and I did not dissolve the sugar, used it like salt in a salt bar.


 

That's very interesting! The batch in which I used 10% sugar (all white granulated) turned out very soft, spongy, and was easy for me to dent by pressing it with my finger, and it stayed dent-able like that for over a year. For what its worth, I completely dissolved the sugar in my water amount.

Sounds like I'll have to try making a batch with un-dissolved sugar!


IrishLass


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## DeeAnna (Feb 2, 2015)

Sugar is highly soluble in water, so I'm guessing you either need to add a modestly small amount (your 3% ppo, Irish Lass) or add a LOT, like Carolyn did -- more than the amount needed to saturate the liquid in the soap. That's just my guess, however!

Adding salt to a bar is playing with the solubility of the soap molecules in the watery liquid phase. (Yes, even bar soap contains liquid trapped in its structure!) Salt reduces solubility of soap in water, so by adding some salt, you're forcing some of the soap to change from being a liquid to being a solid crystal. More solid crystalline soap => harder soap. Salt will also reduce the solubility and lathering ability of the soap to some extent. Since lauric and myristic soaps (made from coconut oil, palm kernel oil) are more soluble in water than soaps made from the other fatty acids normally found in soaps, you'll see less change in hardness, lather, and solubility from adding salt to a high coconut oil soap than from adding salt to a high lard or olive oil soap, for example.


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## MorpheusPA (Feb 2, 2015)

In SoapCalc, I look at durability of the bar as Hardness minus Cleansing.  Cleansing relates to how much soap gets released in water.

So although coconut has good hardness, it also has high cleansing.  it won't be the most durable bar, and olive oil with lower hardness but very low cleansing is potentially more durable.  

There are other considerations, of course--younger Castille is snotty, falls apart, and has low durability.  Aged Castille still has to be stored out of water due to oleic's tendency to really like water.

Salt seems to initially harden a bar, but doesn't seem to have any long-term effect.  The bar's hardness eventually becomes whatever the oil's would have been, then stops increasing.  But salt certainly helps a lot with mold release as the initial hardness is a help.

Although I use sugar, it's to increase lather stability and bubbliness.  I can't say I've noticed any hardness increase for the amounts I use (about 1 tsp PPO).

One thing sugar will do is increase the tendency of the soap to go to full gel.  Gelling solidifies a soap faster than not gelling will, so that does help with initial hardness.  Since I tend to CPOP soap anyway, my soaps gel.

Over the long term, gelled and non-gelled soaps seem to be comparable in hardness--although I still think soaps that gelled are a touch harder even years in.

For the most part, solid oils (or well-aged olive soap) will create a harder bar.  For bar hardness, I'll go to 30% soybean wax.  Too much more makes the bar waxy and gives very spare and weak lather.  Soy wax also has the advantage of being very inexpensive.

Other oils that increase hardness are coconut, palm, and most of the butters.

For durability, just check the cleansing number and subtract from hardness.  If that number is too low (under 15 is my guide), the bar durability won't be great.  But sometimes that's exactly what I want because I want the cleansing factor.  My gardener's soap is rock hard, but not very durable due to the rich, bubbly lather.


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## MorpheusPA (Feb 2, 2015)

Sorry, I forgot cure time!

Longer cure times lead to harder, more durable soap.  Four weeks is just fine, but it's the bare minimum.

I found some soap recently that had cured for four years in open air.  So far, each tiny test bar is lasting ages while producing thick, stable lather.

While curing for four years is not realistic for any of us, the longer the cure you can give it, the harder and more durable the bar will be.

Personally, I prefer to give Castille ten to eleven months to cure--so my Christmas 2015 Castille soap is already in process and will be done by the end of February.  By December, it'll be awesome, hard, durable soap.

Most other soap is just fine at eight weeks--and you can certainly use it at four if you want to, just realize it's going to get better.


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## chloe (Feb 4, 2015)

Thank you! You guys have def answered my questions!


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## penelopejane (Jan 15, 2017)

DeeAnna said:


> Sugar is highly soluble in water, so I'm guessing you either need to add a modestly small amount (your 3% ppo, Irish Lass) or add a LOT, like Carolyn did -- more than the amount needed to saturate the liquid in the soap. That's just my guess, however!
> 
> Adding salt to a bar is playing with the solubility of the soap molecules in the watery liquid phase. (Yes, even bar soap contains liquid trapped in its structure!) Salt reduces solubility of soap in water, so by adding some salt, you're forcing some of the soap to change from being a liquid to being a solid crystal. More solid crystalline soap => harder soap. Salt will also reduce the solubility and lathering ability of the soap to some extent. Since lauric and myristic soaps (made from coconut oil, palm kernel oil) are more soluble in water than soaps made from the other fatty acids normally found in soaps, you'll see less change in hardness, lather, and solubility from adding salt to a high coconut oil soap than from adding salt to a high lard or olive oil soap, for example.



Hi DeeAnna, 
I am sorry for resuscitating and old post but I was wondering if you could please explain to me if the above means that salt in soap makes it harder just in the first few weeks as it cures or forever. 

Thanks.


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