CP liquid soap dry and crumbly

[Fsm_Soap]

Hey there soap experts, I'm looking for help as I'm somewhat stumped.

I have made 100% coconut oil cold process liquid soap quite a few times, easily and with success. This is the recipe I use:
200g coconut oil
170g distilled water
57g koh

1. Mix the koh & water
2. Allow to cool to room temp
3. Add to oil
4. Blend 2-4 mins, rest 10 mins (continue until soap has gone through all stages and can no longer be stick-blended anymore)
5. Cover tightly and leave to rest

2 consecutive times yesterday however this recipe & method completely failed and I have no idea why. What I'm left with after saponification is a dry, hard crumbly soap not paste (as seen in the picture). The first batch wasn't lye heavy. The second batch appears to be. I measured everything very carefully (triple-checked the amounts!).

Is it perhaps that my lye mixture wasn't fully cooled to room temp? I did check but maybe it should have been cooled further?
Is there a problem with my koh? (I have used koh from this same stock previously with success though)
Is it something to do with my blending? Not enough? Too much?
I have made multiple CP soap bars with this same stock of coconut oil so I doubt that there's anything wrong with the oil
I live in a humid environment, can that have any effect?

I've made made at least 3-4 batches using this same method and recipe before so I really have no idea what's going on now Please help!

 

[ResolvableOwl]

This is bizarre. The recipe is fine, apparently you know what you're doing, and you're using the same ingredients as before.

Two things, though improbable, but check them anyway:

• air bubbles, that you accidentally created whipped soap by blending in some air, and just like cream is liquid and gets solid when whipped, soap becomes stiffer as well when you whisk it. I can't really imagine this goes so far that it becomes brittle, but I'm out of other ideas.
• Measuring/weighing: Do you use the same scale for all measurements? Does it work reliably? Have you tared it properly with all new containers? That sounds like stupid errors, but everyone makes stupid errors , and a simple, reliable recipe doesn't just fail without reason. Lye-heavy is a bad sign.

In general, it isn't needed to do so much SBing. Once you have reached stable emusion (might be after <1 min already, but of course depends on batch size and SB power), you can leave it alone. It'll need some 1…2 days until safe completion anyway. A smooth mix (spatula) without unmixed stuff around the bottom and side walls is a lot more important than SBing to thickest possible trace in the middle and forgetting about the walls.

Your KOH, while it could “go bad” (e. g. by pulling moisture from the air), that would cause the saponification to be incomplete, i. e. residual oils, not lye-heavy. That can't be the culprit.

For the crumbly batch: As you noted, it should be the right recipe, so chances are that the soap might come out fine eventually. Dilute it in small steps, say 50 mL distilled water at a time. Let it soak for a few hours and stir weill until it has become homogeneous (ideally: transparent). Do a zap test and a clarity test – if both succeed, your soapmaking was successful in the end. If not, report back your new observations.

 

[Fsm_Soap]

Thank you so much @ResolvableOwl! Really appreciate the detailed reply! I am indeed very confused. Actually I need to make a correction to my previous post. I made my first batch with an existing stock of koh and then thinking that the koh was the problem I made my second batch with a new stock of koh. But I just assumed it was something wrong with my method and recipe when the second batch also failed. I even made a third batch after my initial post and when that also failed I went back to reevaluate all 3 batches.

Batch 1:
-Existing koh which worked fine previously
-Texture is like Styrofoam (hollow sound when tapped & crumbles easily)
-Not lye-heavy

Batch 2:
-New stock of koh
-Batter never got to the taffy-like stage
-End result felt more like soft bar soap but still crumbled when I tried to scoop it up
-Lye-heavy

Batch 3:
-New stock of koh
-Similar results to batch 2 - batter was shiny and smooth, not taffy-like
-Aggressively stick-blended to see if it made any difference - when doing this some liquid started to seep out and then eventually got incorporated back in again
-End result is similar to batch 2 - something like crumbly bar soap
-Lye-heavy

I checked that my scale is working properly by weighing a few stock items and it seems to be fine. I'm quite sure I measured everything correctly but yes I could have made a mistake.

I'm starting to think I have a couple of different issues now. Perhaps I made some mistake with the first batch (I still need to figure out exactly what). And maybe my new stock of koh is actually naoh (my supplier could have made a mistake?). That would explain why the second 2 batches are lye heavy and have a different texture. I really can't think of any other explanation if my recipe, measurements & method are correct.

I have 2 things to try now:
1. I still have a very small amount of my old stock of koh so I will carefully give that another try (keeping in mind all the points you made) and see what happens.
2. I have to dilute a little bit of all 3 batches and see what happens (will do so in a day or two)

Will post back here once I try this. Until then I have one more question. Is there any easy way to confirm (without making more soap) if the koh I have is actually koh and not naoh?

 

[ResolvableOwl]

Until then I have one more question. Is there any easy way to confirm (without making more soap) if the koh I have is actually koh and not naoh?

That would be a thing! It'd explain quite some of your troubles, like the hardness and excess lye. A few reasonably easy ways to distinguish KOH from NaOH:
Flame colouration. Use a pale flame (alcohol, gas stove, esbit) and carefully put a bit of the substance in question into the flame. If it is a pure potassium compound, the flame turns pale pink. If there is some sodium in it, it will be bright orange-yellow (however, even a few % of NaOH will cause a bright yellow that might cover other colours).
Solubility in alcohol – if you have pure (>95%) ethanol or isopropanol at hand: KOH dissolves much more readily in these than NaOH does. If you can dissolve anything above 5% within an hour, and the solution gets a bit syrupy, then chances are that it's KOH. Again, ignite the vapours to test for flame colouration.
Salti-thickening: If you have some runny, clear liquid soap at hand (ideally not one from 100% coconut, but with long-chain oils like olive, sunflower or palm in it), add a bit of the dissolved lye in question. If it is KOH, nothing will happen. But if sodium is in there, the soap thickens up, becomes murky, solid, and/or even starts to rice/separate. To have a comparison how a positive test looks, you can test this separately with some NaCl (kitchen salt).

These tests only work with reasonably pure lye. If there is some, say, 10% NaOH contamination in your KOH, they'll tell you that there is sodium in there, which might or might not be an issue for soapmaking. It's annoying when it turns out you can't rely on your supplier, but if it is as easily to solve like using a bit more water, then you might live with it. Though, the concentration (your lye-heavy outcomes) is still an issue, for which there is no other option than titration to find out.

In case the suspicion of wrongly labelled/contaminated lye is confirmed, you should consider reaching your supplier and clarify it with them.

 

[Fsm_Soap]

Thanks again @ResolvableOwl! This is all so very helpful!! I will try one of these methods and once I have everything figured out I will post back here. Hopefully all this can be of use to someone else too. It's a good thing all my batches were so small! Otherwise there would have been a lot of ruined soap. Fingers-crossed I can figure out where it all went wrong.

 

[amd]

Is there any easy way to confirm (without making more soap) if the koh I have is actually koh and not naoh?

Not exactly... at least I don't think so. There may be some information here (additional links and information in the source that may be helpful)
https://classicbells.com/soap/lyePurity.asp

 

[Fsm_Soap]

@ResolvableOwl, thanks again for all your help. Unfortunately I still didn't get a chance to test my lye but in the meantime something interesting happened. I made another batch of soap with my old stock of koh and it turned out exactly like batch 1....crumbly like Styrofoam. I was so frustrated at this point....I had 4 batches of messed up liquid soap and it was all just sitting around taking up space. I dumped everything in a pot and double boiled it with the hope of turning it into something more useable and less lye-heavy. Lo and behold, an hour or so later I saw it turning into the liquid soap paste that I was expecting! I let it cook for another hour then left it to set and now it has turned into perfect liquid soap paste that is not lye heavy either. Any idea what has happened? I'm guessing that something is wrong with my method? Maybe the lye solution was too cold? That still doesn't explain the difference in textures between the 2 stocks of koh. On another note, I did dilute them before cooking and they all made decent liquid soap. I'm reluctant to give it another try until I finish off the soap I have right now. Anyway I just wanted to leave an update here in case it's useful for anyone else.

 

[ResolvableOwl]

I have had styrofoam-like HP soaps (LS and bar soap) before, and I traced it back to water losses via evaporation. At some point into the saponification, the batter became so viscous that the few air bubbles from stirring wouldn't release, and end up in a whipped-cream like texture. I haven't had that for CP liquid soap though. Maybe stubborn pockets of coconut oil unwilling to react? What is your room temperature/is coconut oil liquid at RT for you?

In any case, I'm glad that your batches went out fine in the end! It'd be better if you/we could understand what went wrong in the first place. But you at least learned that the initial investment was salvageable.

 

[Fsm_Soap]

Thanks for all the insights! Yep, my coconut oil at room temperature is liquid. I generally always soap at room temperature. I've still not given up on finding the root cause. I'm glad I salvaged these batches but I hope to eventually figure out what happened and will definitely post back here if I manage to figure things out.

 

[Fsm_Soap]

So it's been a while but I only got back to this now and wanted to share my latest findings. Completely forgetting the mess I went through last time I went ahead and made a 500g oil batch of liquid soap using my 'potentially not koh'. Mid-way through stick-blending it all came flooding back but I had to finish what I started. What I ended up with was the same as one of my previous batches; a lye-heavy & mostly solid crumbly soap. I revisited this thread to remind myself of what I had done last time. I had double-boiled all my failed batches and ended up with perfect liquid soap paste. So I set about doing that but this time it was a no-go. It only turned into a slightly liquid batter solidifying as soon as I took it off the heat. Not wanting it to go to waste I recalculated the recipe as if it was naoh and rebatched it with additional oil & water. I now have some solid soap (albeit somewhat soft due to the additional water).

Next attempt was to treat my questionable koh as naoh. I made a very small batch of my usual coconut oil solid cleaning soap recipe. And the result was almost the same as my usual soap but a little bit softer and ever so slightly off-white. My coconut oil solid cleaning soap is always pure white and rock solid.

I tried testing both lyes over a flame and what I got for both was a yellow/orange flame. I'm not sure if I was doing it correctly though. I held it over a low gas flame with a metal wire with a small loop (lye was sitting on the loop).

So it looks like what I have is not koh or at least not pure koh. It's been almost a year so it might be too late to go back to my supplier but I will still try. In the meantime I have a few questions.

1. How did I manage to get liquid soap paste out of my failed batches last time? I had used 2 different socks of koh. So at the very least if one of them was actually naoh the end result should have been some kind of dual lye soap. But it looked exactly like the soap paste I had successfully made a few times before that.

2. If I assume that what I have now is actually naoh and not koh then why is it not pure white and rock solid like my usual cleaning soap?

3. If what I have is actually some kind of impure koh would it behave in the manner I have described above?

I'm stumped. Is this something anyone can help me figure out or is it almost definitely a problematic stock of lye that I should figure out with my supplier?