Can I used a failed rebatch hard bar soap in a new liquid soap recipe?

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Astro

Active Member
Joined
Mar 1, 2020
Messages
37
Reaction score
32
Location
South Africa
Story so far... I made a batch of bastille soap with lavender EO but overdid the mica decoration on top which I hated so decided to rebatch for the first time. Impatience being my middle name I didnt wait long enough for the soap to melt and kept adding more water.... oops! After cooking for over 24 hours in the slow cooker it was still too wet so I put it in the gas oven on 130 and did another 12 hours of cooking, stirring occasionally. Still too wet but I molded it and overnight it has a slightly hardened top but is still very soft inside. I think it is going to take months to evaporate the water and I have no idea when to attempt to cut it.
I will be making some liquid soap soon and would like to know if I can use some of the rebatch bar soap in the recipe. For example, dissolving some of the bar soap in the full liquid before adding the KOH. I know I wont get a clear liquid and the KOH is likely to burn off the lavender EO, but will it adversely affect the liquid soap? Is it likely to make the liquid soap gloopy?
Any help or suggestions would be appreciated.
 
I hope someone chimes in because I'm not 100% sure that's a feasible plan and I'm leaning on the yes, try it side. On a side note, a lot of people here are impatient but this is not that kind of craft for impatience. Your experience is a much nicer consequence of that. You're going to have to force yourself to be patient in regards to rebatching, if you do it again. A lot of us hate it because it's time consuming but sometimes, you gotta do whatcha gotta do to fix/save a soap.
 
You can try it, but I think it would come out "gloopy" as you said, and possibly snotty too. A lot of people try making liquid soap out of bar soap, and it just does not work.
However, I'm not sure how it would turn out putting the melted cp rebatch into a KOH liquid soap. I honestly don't think it would work, but have never tried it, and don't know if anyone has tried it, so who knows, it might.
I think it would be worth the experience to experiment.
 
Just to clarify, you would be adding other oils for your KOH to saponify, right? Not just adding KOH to bar+water? Because that would just give you really caustic soap.
Depending on the percentages, you might just get a croap: too hard to be a cream/liquid soap, too soft to be a bar soap. A lot of people make croaps on purpose, particularly for shaving soap, but without knowing what oils you've saponified with NaOH, which you're planning to saponify with KOH, and your percentages on all of the above, it's hard to guess what you'd have.
 
It depends on how much sodium (NaOH) soap is in proportion to the potassium (KOH) soap in the final mixture. And on the relative proportions of the fatty acids in the finished soap. So it's hard to give a "for sure" answer.

If you use a high % of sodium soap -- I'm guessing something around 40% or more -- the result could be a "liquid soap" that wants to revert to a not-pourable paste even as you add more and more water.

If you use a little bit -- say 10% sodium soap or less -- it should be fine.
 
Re making liquid soap from bar soap.

Some years ago, I made my very 2nd batch of soap at home with 35% castor oil. [PAUSING to laugh]

Anyway! It was a charcoal soap. I tried to re-batch it with oats, songs and prays. but I understand now why my finger continued to literally sink right through the 'bars' with the lightest touch, even after a lot of cure time.

Frustrated, I diluted it over an extended cook with about 50% water if my memory serves me well. We used it up as liquid soap and absolutely loved it! It was a nice fluke of high cleansing and high conditioning. The charcoal never settled and if the colloidal oats should have made it go off because of the laws of science, they never did, possibly because we used it quickly too. That accident taught me how loveable castor oil is. However, the issue with mine might be different to yours. Mine was simply a matter of formulating incorrectly because I had not yet understood the different oil properties and setting proportions accordingly. Specifically, while I was using NaOH with hopes of getting solid bars, the 'bars' were never going to harden because of such a high percentage of castor oil.

Unfortunately, I stopped taking notes when I thought the batch had failed. My thinking was that I would just try something crazy to see what would happen next, ie before I dumped it. Unsure whether this misadventure is at all helpful but just thought I'd share anyway. It's a mildly bitter but very sweet memory for me!
 
Last edited:
Thank you all for the input and advice.

Just to clarify, you would be adding other oils for your KOH to saponify, right? Not just adding KOH to bar+water? Because that would just give you really caustic soap.
Depending on the percentages, you might just get a croap: too hard to be a cream/liquid soap, too soft to be a bar soap. A lot of people make croaps on purpose, particularly for shaving soap, but without knowing what oils you've saponified with NaOH, which you're planning to saponify with KOH, and your percentages on all of the above, it's hard to guess what you'd have.
I would be making a liquid soap and just want to add in some of the bar soap to the batch so I dont waste it.
The recipe is
Olive Oil 80%
Coconut Oil 13.33%
Castor Oil 6.67%
Lye concentration 33.33%

And way too much water on rebatch.:smallshrug:

It depends on how much sodium (NaOH) soap is in proportion to the potassium (KOH) soap in the final mixture. And on the relative proportions of the fatty acids in the finished soap. So it's hard to give a "for sure" answer.

If you use a high % of sodium soap -- I'm guessing something around 40% or more -- the result could be a "liquid soap" that wants to revert to a not-pourable paste even as you add more and more water.

If you use a little bit -- say 10% sodium soap or less -- it should be fine.
I was thinking of using just a little bit of bar soap (5% superfatted) into the batter, mixing into the oils before adding the KOH, and reducing the liquid soap superfat from 3 to 2%.
I can just imagine the gloopy mess if I added too much of the bar soap. :nonono:

I don't know if this will help you... but a few years ago we had this discussion
https://www.soapmakingforum.com/threads/cream-soap-from-soap-scraps.63087/and I was able to make a somewhat decent cream soap from soap scraps. It worked best in jar packaging (rather than a pump dispenser) but it was useable.
Thank you - I will be reading this thread thoroughly :)
 
It depends on how much sodium (NaOH) soap is in proportion to the potassium (KOH) soap in the final mixture. And on the relative proportions of the fatty acids in the finished soap. So it's hard to give a "for sure" answer.

If you use a high % of sodium soap -- I'm guessing something around 40% or more -- the result could be a "liquid soap" that wants to revert to a not-pourable paste even as you add more and more water.

If you use a little bit -- say 10% sodium soap or less -- it should be fine.
Do you think that stubborn paste, if you will, would be pliable enough to use for a travel soap?
 
Gosh, that's hard to say without actually trying it. But I do know Susie uses 100% KOH paste as a travel soap -- her "Travel 2 Go" soap -- and I've tried her idea myself with good results. So I'd think a NaOH-KOH paste would work okay as well.
 

Latest posts

Back
Top