My unintended experiment and what came out of it

[natik]

Last week and made @IrishLass creamy cocoa/shea GLS. Liked it, but felt like it didn't have enough bubbles for me. So I went on a quest to make something similar, but bubblier. I searched through this forum, internet, couple books on liquid soap making and decided on this:

I measured my ingredients and made the HP soap. After saponification and couple hours of cooking, it didn't look like the normal HP soap I did before. The paste was very white, it never completely hardened, I could easily mix it with the spatula and if I lift the spatula - it would create thread-like strings. Something was definitely wrong. So I decided to dilute it do the clearance test. It came very clear, but the PH was testing between 12-13 on the strip. I could figure out what went wrong. So I proceeded to neutralize it with 20% Citric Acid solution, took me about 80 ml of it to get to normal PH. While doing it, I kept SB it, so I ended up with whipped soap. I put it aside, checked my recipe, could find anything wrong with it and decided that I made mistake in measuring the lye.
I was still determined to make it right, so went ahead and made another batch. 2 hrs into making second batch, same thing happened. Clearance test is OK, PH is high. This time I didn't dilute it with water and started diluting and SB it with Citric Acid solution. This time it took me roughly 40% less water to dilute it and get to a thick creamy consistency and left it at that.
At this point I was very frustrated, rechecked the recipe and finally realized what went wrong. Apparently, while weighing my oils, I looked at oil % instead of g. So I put 50g of coconut oil instead of 75g, 20g of olive oil instead of 30g and so on. My total oil weight was supposed to be 151g, instead I ended up with 100g. Yet, liquids and lye I measured correctly, so I ended up putting 50% more lye and liquids than intended.

I went ahead and made the third batch correctly, which turned out as expected.

So, today I woke up to 3 completely different types of soap.
The first batch of lye heavy soap (diluted and neutralized yesterday) looking nice and thick, bubbles well and feels fine on the skin.

The second batch of lye heavy soap (neutralized yesterday, but with less water and SB for longer time) looks like whipped cream with very little yellow watery liquid on the bottom (see picks). It dilutes clear in water, no cloudiness (no free fat?) and PH on the strip between 8-9.


Here comes my question (sorry for the long introduction): did I ended up with the cream soap? Is it possible without using extra stearic acid? I read somewhere that overmixing liquid soap may lead to fat separation. So theoretically, it could be whipped oils on top with lye settling on the bottom, but then the top wouldn't leather and bubble, right?
I am really interested in experienced soaper's opinion, especially those with some chemistry background.

 

[DeeAnna]

Without spending a lot of time trying to reconstruct what you did, my best guess is you waaay overneutralized the soap with citric acid and ended up with whipped fatty acids, not whipped soap. Sure ... fatty acids can be whipped and, yes, you can aerate them to create foam, but they are not actual soap.

You cannot, cannot use pH alone for neutralization, because the pH that is "fat-alkali neutral" for a particular soap (meaning a soap with no excess lye and no excess fat) is not the same for ALL types of soap.

One soap formulation might be fat-alkali neutral at a pH of 11. Another might be fat-alkali neutral at 9.5. If you know which one you've got just from pH alone, you're a better soap-chemistry geek than trained and experienced soap scientists.

You're also saying you're getting readings in the 12-13 range which tells me you're using strips with a range of 0-14 pH units. Even if you could neutralize soap with a simple pH test, this type of strip isn't remotely precise enough for this type of adjustment.

To do a neutralization properly, titrate a sample of soap with a dilute acid to a precise pH endpoint. Test this pH to 0.1 pH unit or better using a properly calibrated pH meter or pH indicator -- NOT test strips. Then calculate the correct amount of acid needed to accurately neutralize the entire batch based on the amount of acid used in the titration. Note this is NOT a simple pH test.

 

[natik]

Thanks, @DeeAnna
I was hoping for your answer. Still not sure what exactly happened there. I left it alone for several days and then mixed all batches together, then left them for another day and there was only small amount of foam left on top which I have discarded.
The soap feels OK now.
I know the strips are not accurate, I have learned that much from this forum, but I have to go by something to figure out whether the soap is safe. I also used Phenolphthalein, not sure if it is any better. Titrating the soap is too much for me. I am new to soaping, so I am making very small batches and if something goes wrong and I am not sure how to fix it - I would better discard and try again. Anyway, for now, I enjoy making soap more that actually using it. My newfound hobby.

 

[Susie]

Phenolpthalein is not better than strips. I can tell you now that it will turn pink. It is supposed to. It is alkaline. There is no need to neutralize soap. Just use a proper soap calculator on the front end set to 2% superfat and your soap will not need any of that. Also, learn to zap test, and you can do away with all of the other "testing" methods that are going to give erroneous answers. Hope this helps.

 

[natik]

Thanks, @Susie . It was a while ago, I think, I still diluted this soap and used it, it was OK. Now, just like you suggested, I don't bother with strips any more. I do zap test and go with that. All the soaps come out Ok.