Whats a good way to add hardness without changing your oils/butters?

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Mollywolly

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I'm formulating a recipe using soapcalc.com and the conditioning value is where I want it to be. However, My hardness value isn't as promising. Is there a way to harden the bar without changing the oils/butters? Any additives I can use? Herbs, Powders, Clays, Etc? Thank you in advance for any advice/ knowlege/anything that requires work to explain.
 

TheGecko

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The Soap Bar Qualities of soap calculators don't mean what you think they mean.

The "Hardness" isn't about the physical hardness of the bar. You can make a bar that is as hard as a brick by reducing water, curing for several months, adding salt. It's more about how soluble (dissolvable) your soap is. Too low and you soap will just melt away. Too hard and you're not going to get much soap to clean with.
 

Mollywolly

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The Soap Bar Qualities of soap calculators don't mean what you think they mean.

The "Hardness" isn't about the physical hardness of the bar. You can make a bar that is as hard as a brick by reducing water, curing for several months, adding salt. It's more about how soluble (dissolvable) your soap is. Too low and you soap will just melt away. Too hard and you're not going to get much soap to clean
That being said: What do you like to use to harden your bars? Thank you so much for explaining the hardness factor by the way.
 

earlene

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Rice water instead of plain water, for some reason does harden up soap, per some anecdotal comments, and I have experienced this as well. Salt does, of course. Apparently Sodium Lactate contributes to a longer-lasting bar, as well as helping the bar to harden up sooner to get it out of the mold faster. Besides using a higher lye concentration (less water), another factor may be your superfat. A lower superfat logically means there is less unsaponified oil in the soap, which logically would produce a softer bar under the right circumstances, which I think would depend on the actual recipe. Oh, and vinegar. I ended up with extremely hard soap using vinegar in place of water in my lye solution. There are additional calculations for the lye, because vinegar also reacts with lye.

I would say that of all the soaps I have made, vinegar replacement made the biggest difference in hardening up the soap. And salted rice water the second biggest difference.
 
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That being said: What do you like to use to harden your bars? Thank you so much for explaining the hardness factor by the way.
The answer to that is going to depend on your recipe. We encourage folks to share their full recipe (including all additives), and their process. Otherwise, we might recommend something that doesn't accomplish what you want to accomplish, because it doesn't play well with what you are already using. :)
 
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Using brine, or using vinegar as your water component will harden a bar.
Have you fully researched the fatty acid profiles? Increasing the stearic and palmitic components will create a longer-lasting and firmer bar. However, coconut oil, high in lauric acid, will make you bar really hard BUT if used in too high a quantity it will be too cleansing and irritating on the skin AND it will lather so well that the bar will disappear in no time.
 

Anstarx

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Do you want the soap to be harder and last longer in the long term or just harden faster so you can cut faster?
I've used sodium lactate and salt, which does the latter and doesn't change the long term hardness IMO.
 
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Another longtime sodium lactate user here. I use it at 3% of oil weight, likely on the high side. I dump it in my lye solution just before adding the oil mixture. Good luck to you.
 

Dawni

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I agree with the rice water and flour. In my case, my hardest bars are the ones that use the aforementioned, and also rice puree. No idea why.. Have not found scientific data to explain it but I've been making this soap for a couple of years now, and it's always the hardest. Also lasts quite a while so the longevity factor is also there. At least for me.

Careful with salt though, and brine. It does help with hardness but it might also limit your lather, depending on your recipe... Notice how usually, a lot of salt in recipes also have a high coconut oil amount (salt bars, soleseifes).
 

Mollywolly

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Rice water instead of plain water, for some reason does harden up soap, per some anecdotal comments, and I have experienced this as well. Salt does, of course. Apparently Sodium Lactate contributes to a longer-lasting bar, as well as helping the bar to harden up sooner to get it out of the mold faster. Besides using a higher lye concentration (less water), another factor may be your superfat. A lower superfat logically means there is less unsaponified oil in the soap, which logically would produce a softer bar under the right circumstances, which I think would depend on the actual recipe. Oh, and vinegar. I ended up with extremely hard soap using vinegar in place of water in my lye solution. There are additional calculations for the lye, because vinegar also reacts with lye.

I would say that of all the soaps I have made, vinegar replacement made the biggest difference in hardening up the soap. And salted rice water the second biggest difference.
Amazing information. I've never heard of using rice water before, and I may give it a try for a personal recipe. I love bars that last long.
 

Mollywolly

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Do you want the soap to be harder and last longer in the long term or just harden faster so you can cut faster?
I've used sodium lactate and salt, which does the latter and doesn't change the long term hardness IMO.
Is there a difference really? Wouldn't soap that cures faster be generally harder and longer lasting or does it depend on the recipe?
 
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Is there a difference really? Wouldn't soap that cures faster be generally harder and longer lasting or does it depend on the recipe?
Coconut oil (high in Lauric acid) creates a hard bar, but is very soluble, so the soap bubbles well, but gets used up faster.
Fats high in palmitic and stearic create longevity - i.e, yes they do harden a bar, but are not very soluble ( they're not there to promote lotsa bubbles) and thus they last longer.
 
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I've used sodium lactate, salt and bees wax for a harder bar. Then I found out that what I really wanted was a bar that lasted longer, not just harder (as in faster out of the mold and can cut earlier). All three cut the lather to some degree.

When I found out what I wanted was longevity, I got rid of most of my coconut oil and started adding rice of some sort to my soaps. I'm down to one bar of @Dawni 's triple rice soap so will be doing another couple of batches this month. It makes a lot of difference in the longevity of my soaps. This time I will be making ice cubes from the rice water and rice puree, so I have that part made...sort of like master batching my lye water. And I love the feel of the lather on my skin better than I did before going to rice.

I finally bought some sorbitol and will be trying that to increase the bubbles, but since I already like the feel of the lather, the sorbitol is only for my grandson who loves bubbles, not lather.
 
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What these will not do is change the longevity of your bar even those the above suggestions will help you with unmolding sooner. I am one that uses vinegar in all my soaps because it allows me to unmold sooner and helps my low CO soaps lather better. SL I have only used a couple of times in my many years of soaping so I am no help there. I do agree Rice Water helps and Lye concentration helps, My average Lye Concentration is 33% depending on my formula.
 

Mollywolly

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I have never used the salt but I am willing to try. I don't know how to use the salt or how much to put so I don't know
I highly suggest you try, not just to answer the question, but gain some experience as well to see if you like it or not. I'll be dabbling in it pretty soon myself
 

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