Brine soap who created this soap

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Does adding salt to soap made with potassium hydroxide turn it into a batter that hardens and can be cut into bars?
A very categorical “It depends™”. @AliOop is right that with the addition of sodium salts to KOH-based LS in the low percent-range (salt curve), great and/or weird things can happen from the perspective of a LS soapmaker.
Sodium soaps have a tendency to “stay with themselves” and struggle to be evenly dispersed in aqueous solution. At very low concentration, this can be exploited to thicken LS, but once there's enough sodium for curdling, parts of the soap will separate out into a disgusting curdled-egg like snot – a failure from the LS perspective.
But what if you continue to add table salt? More and more sodium is available, more soap will precipitate, until most of the soap has converted to this weird sodium jelly – which is nothing else than the soap slurry that you get when you dissolve soap bar shreds in hot water for regular salting-out!
Even more salt, and salting-out will take place. Potassium wants to stay in aqueous solution, so it'll be wherever the water is = mostly in the lower brine layer. Yes, there will be some indefinite amount of potassium carried over into the bars, but then, dual-lye bar soap is a thing too. If you worry, you can salt-out a second time.

tl;dr: It is totally possible to convert LS into bar soap by NaCl salting-out. (It's another question if it is sensible, given that the fewest LS recipes/oil blends make a decent bar soap).
 
A very categorical “It depends™”. @AliOop is right that with the addition of sodium salts to KOH-based LS in the low percent-range (salt curve), great and/or weird things can happen from the perspective of a LS soapmaker.
Sodium soaps have a tendency to “stay with themselves” and struggle to be evenly dispersed in aqueous solution. At very low concentration, this can be exploited to thicken LS, but once there's enough sodium for curdling, parts of the soap will separate out into a disgusting curdled-egg like snot – a failure from the LS perspective.
But what if you continue to add table salt? More and more sodium is available, more soap will precipitate, until most of the soap has converted to this weird sodium jelly – which is nothing else than the soap slurry that you get when you dissolve soap bar shreds in hot water for regular salting-out!
Even more salt, and salting-out will take place. Potassium wants to stay in aqueous solution, so it'll be wherever the water is = mostly in the lower brine layer. Yes, there will be some indefinite amount of potassium carried over into the bars, but then, dual-lye bar soap is a thing too. If you worry, you can salt-out a second time.

tl;dr: It is totally possible to convert LS into bar soap by NaCl salting-out. (It's another question if it is sensible, given that the fewest LS recipes/oil blends make a decent bar soap).
Thank you for the explanation. The second page of Franklin recipe is missing, so I don’t know if the soap was actually cut into bars. I’m very curious about the qualities of historical soaps in our country. The Franklin soap was salted out. The soap I made with the Bayberry wax is hard, but not crumbly. It has a salty taste, no zap, only a little soapy. Perhaps I didn’t use enough lye in the water? Is there a way to test the fat content in soap?
 
Clarity test – pure soap dissolves into warm distilled water at some 5% into a clear solution. If it's turbid (milky) and settles at the top, something oily is in there, it might be superfat (too little lye deliberately or by accident), or unsaponifiables, or EOs/FOs, or waxes…

Or, more specifically, test if your brine is zappy. If it is, then you have used enough lye. Anyway, give it some time to dry and cure and sort itself being a bar soap, it might undergo dramatic changes in texture and skin feel.
 
Clarity test – pure soap dissolves into warm distilled water at some 5% into a clear solution. If it's turbid (milky) and settles at the top, something oily is in there, it might be superfat (too little lye deliberately or by accident), or unsaponifiables, or EOs/FOs, or waxes…

Or, more specifically, test if your brine is zappy. If it is, then you have used enough lye. Anyway, give it some time to dry and cure and sort itself being a bar soap, it might undergo dramatic changes in texture and skin feel.
Thank you! I ran the test on a small piece of my Franklin soap. At first everything was milky and then solution, but then it separated into two layers. I don’t know what the effect of the bayberry wax would be on the top layer, it does seem to be fat heavy, even though no oily spots appear. I rubbed a little of the milky white part on top of my hand. It seems oily. Should I re-batch it with more lye? The bottom layer is salty. I tasted it. 😜 Would that cause the Top layer to precipitate out, even if it was soap? I’m still trying to figure out If historic boiled and grained soaps are related to salt bars.
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When you have tasted it and your impression was “salty” and not “zappy”, then it's very likely that you were short of lye indeed.
Would that cause the Top layer to precipitate out, even if it was soap?
Salt in soap is complicated. It might cause precipitation/separation, or it might not. It depends on salt concentration, oil blend, residual superfat, FOs etc. And to make things even more complicated, NaOH is a salt by itself too, and can cause salting-out just like NaCl does.
The clarity test (in the spirit of LS soapmaking) is conducted at such weak dilutions (a few % at most) that separation/salting-out is reliably avoided/reversed.

From your description and photo, it is very likely that you indeed have underestimated the amount of lye needed, hence some free fat is floating around.
The bayberry wax itself is chemically not a “wax in the narrower sense” (beeswax and the likes), but a di-/triglyceride, hence similar enough to ordinary oils to be treated/used like an oil.

Your next logical step is indeed to grate up the soap (or a small part of it first), heat it up with some water, and then add lye in multiple small portions and wait for HP-ish saponification in between (no need to waste too much lye). Repeat the clarity test every now and then, to judge if saponification is through. Then it's time for another salting-out.

Keep me/us updated!



The Franklin recipe aside, bayberry wax sounds like a very appealing soap ingredient. Haven't heard about it until you mentioned it here. Does it have a smell?
I've toyed a bit with Japan wax, which is very similar (both botanically and from its properties/FA profile), for bar soap recipes to lower the dependence on animal fats, tropical hard fats, or hydrogenated oils.
 
When you have tasted it and your impression was “salty” and not “zappy”, then it's very likely that you were short of lye indeed.

Salt in soap is complicated. It might cause precipitation/separation, or it might not. It depends on salt concentration, oil blend, residual superfat, FOs etc. And to make things even more complicated, NaOH is a salt by itself too, and can cause salting-out just like NaCl does.
The clarity test (in the spirit of LS soapmaking) is conducted at such weak dilutions (a few % at most) that separation/salting-out is reliably avoided/reversed.

From your description and photo, it is very likely that you indeed have underestimated the amount of lye needed, hence some free fat is floating around.
The bayberry wax itself is chemically not a “wax in the narrower sense” (beeswax and the likes), but a di-/triglyceride, hence similar enough to ordinary oils to be treated/used like an oil.

Your next logical step is indeed to grate up the soap (or a small part of it first), heat it up with some water, and then add lye in multiple small portions and wait for HP-ish saponification in between (no need to waste too much lye). Repeat the clarity test every now and then, to judge if saponification is through. Then it's time for another salting-out.

Keep me/us updated!



The Franklin recipe aside, bayberry wax sounds like a very appealing soap ingredient. Haven't heard about it until you mentioned it here. Does it have a smell?
I've toyed a bit with Japan wax, which is very similar (both botanically and from its properties/FA profile), for bar soap recipes to lower the dependence on animal fats, tropical hard fats, or hydrogenated oils.
I did the test on the salt scraps that I had salted out for comparison. I know for sure that those scraps were fully saponified. There is no separation in that batch.

I had already put the Franklin soap back into the pot when I saw your response. I guess I should have test the lye water first by floating an egg like Jane did? Not sure how much to use this time, but I’ll figure it out.

my bayberry wax used to have some fragrance, but not as strong as from the species Pimenta racemosa from the West Indies. I found a supply for soap making that’s available at From Nature With Love. The Bayberry is available in beads, which would work well for soap. Bayberry has a lower melting point than beeswax. The difficult part is not having a definitive lye ratio for Bayberry. Is there a way to test for that in a specific batch of botanical wax?
 
test the lye water first by floating an egg like Jane did?
Floating egg test just measures density, and in your case you won't know if the dense stuff is NaCl or NaOH. It's only then of some use if you know that you only have NaOH (or KOH if from inland wood ash) and you're unsure about the concentration.

The difficult part is not having a definitive lye ratio for Bayberry. Is there a way to test for that in a specific batch of botanical wax?
Well, you could either search in the literature (like Wikipedia, that cites Cameo, who themselves refer to an older version of the Wikipedia article as their source…). LipidBank.jp doesn't list it. But some vendors do. I'd guess such numbers around 0.15 do sound somewhat reliable, in line with other oils that have comparable average FA profile (tamanu oil, japan wax, palmitic acid).
The hardcore method is to carefully prepare a lye-heavy soap from the pure oil/fat/wax, and titrate the excess lye with acid and a pH indicator. No fun, I can tell you, but that's the way it is done in the labs from which such numbers come from in the first place. In some way, that's similar to what you're doing here, just in an unsystematic and not very precise way (add lye until it passes the clarity test, but isn't zappy yet).
 
I tested the Franklin soap I made to see if it was fat heavy, and it was. The surprising part was that both the fat solution and the soap solution gelled. I assume that was because salt was present in the soap? I.e. it was a brine soap?

I rebatched the soap with full lye for the weight of the oils in the soap. I ended up with a lye heavy mess, but that is what I wanted. I added distilled water at 3 times the weight of the soap, brought the temperature slowly up to 160°F and cooked it until all soap was melted and in solution. Then I added salt to grain the soap, leaving soap floating on top of lye-heavy salt water. I separated the soap and squeezed it in a cheese cloth to get rid of any excess water. The brownish, lye-heavy water in the pot went down the drain.

I rebatched the soap curds with distilled water at 160°F until the soap formed a homogeneous batter, then poured it into molds. This morning the unmolded Franklin soap looked smooth like white butter.

I ran another test with 5% soap in hot distilled water solution to see if any high fat levels remained. This time all of the soap dissolved. In the picture you can see the first batch on the left with the white fat in solution on top. The solution on the right is from the final rebatch. The solution tasted salty with a very soapy aftertaste, but no zap. The interesting thing to me was that once it cooled, the solution had gelled. Yes, the glass is on it’s side in the last pic.

So . . . Does the gelled solution mean the Franklin Crown Soap is a type of brine soap? Perhaps other historical boiled soaps that were salted out were also brine soaps? (I think I’ve gone full circle back to my original question at the beginning of this thread. 🙂)

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Wow! On paper, it was to be expected that it works like this, but it's amazing that the soap itself knows this too, and knows to behave 😄.
Congrats to you soap! It really looks decent (reminds me of feta cheese or tofu). Be glad that salting-out worked so well (I won't show how my salted-out bars look like). I have to remember the cheesecloth trick – if the soap curds are firm enough, it's a good way to get out more of the brine/“whey”. Now it's time for the boring part (wait the soap to settle/cure into firm bars).

What you, in principle, could have done, is to add glycerol again. Glycerol is water-soluble, so salting-out removes most of it from the soap. Usually we don't talk much about the natural glycerol in soap, since it is there anyway, regardless of CP, HP, or rebatching: hardly anybody knows how their soap would be without glycerol. Except for those who salt out (But then again, the residual salt distorts the assessment of soap properties).

Does the gelled solution mean the Franklin Crown Soap is a type of brine soap?
Not necessarily. It's a peculiarity of soaps of long-chain saturated FAs to be sparingly soluble in cold water, but much better so in hot water. If you have a clear hot solution of sodium palmitate/stearate (mainly from the tallow in your case), the soaps will remember upon cooling that they don't actually like to stay in solution, and precipitate out. They solidify in place, and instead of lumps floating around, they turn into a loose network structure that will hold the surrounding water in place – a gel.

Hard to tell if the salt plays a role there too. Well-known from liquid soap, adding salt will make soap less soluble (also the oleic/unsaturated FAs). So probably it's both: It is common for hot solutions of soaps to gel upon cooling, and some extra salt increases the rate and the amount of FAs taking part in the gelation.
 

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