Hello, sometimes when I test for phenolphthalein after making my liquid soap, there is a slight pink color. Since there is little solution left, I add a very small amount of citric acid to neutralize it. It works very nicely. But citric acid sometimes doesn't dissolve completely. Or it may not mix completely as a white cloudy layer. I have shown examples in the photo. What advice can you give about mixing citric acid completely homogeneously?
How to add citric acid?
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Are you dissolving the CA first in some warm water? If not, you really should. You cannot count on the dilution water in your LS to dissolve it, especially if your diluted soap is no longer warm. CA dissolves much more easily in warmer solutions than in cooler ones.
Are you adding CA because you are trying to neutralize a known lye excess, or because you are trying to lower the soap's pH? I realize this is a hotly-debated topic, but phenolphthalein doesn't actually tell you whether you have a lye excess, because the pH of soap does not directly correlate with lye excess or lye discount.
Also, lowering the pH by any significant amount is not really possible without "breaking" your LS. Here is a good article about that, and another one about how to properly test the pH of soap.
Are you adding CA because you are trying to neutralize a known lye excess, or because you are trying to lower the soap's pH? I realize this is a hotly-debated topic, but phenolphthalein doesn't actually tell you whether you have a lye excess, because the pH of soap does not directly correlate with lye excess or lye discount.
Also, lowering the pH by any significant amount is not really possible without "breaking" your LS. Here is a good article about that, and another one about how to properly test the pH of soap.
Zany_in_CO
Saponifier
See pages 29-30 of Catherine Failor’s book on Making Liquid Soap.
20% CITRIC ACID SOLUTION - Add after Dilution
Make a 20% solution of citric acid & distilled water:
Add 1 oz. Citric Acid powder to 4 oz. boiling water to make a 20% solution.
Stir until clear. (Can be bottled up and stored at room temp until needed.)
Use Rate: 3/4 oz. (1 1/2 Tablespoons) of solution per pound of paste.
TIP: Never add citric acid powder directly into LS without first diluting it or it can throw the soap out of solution. Warm the batch to 140°F before adding the warmed solution. This may result in “snow flurries” -- white flakes floating in the soap. This can be corrected by stirring and reheating if needed.
That's a sign that the LS paste is not completely saponified, and therefore, not ready for dilution. I would wait 24-48 hours to test again -- or longer if need be. The soap will get there on its own eventually.
While not exactly correct, there is a danger of lowering the pH to a point where the solution "breaks". You don't want that. So take good care when adding the 20% CA solution. Done correctly, you can lower the pH but it's not generally recommended for that reason. There's a good article about testing pH of LS here:
https://alaiynab.blogspot.com/2015/05/ph-testing-of-liquid-soap-and-lowering.html
To correct your current situation:
I would pour off most of the batch while leaving the CA particles in some of diluted LS in a microwave container. Reheat to 159° - 160° F. Stir gently until completely dissolved. To avoid foam, do NOT use a whip or stick blender.
HTH
Thank you very much for your reply.
No, I don't add CA to lower the pH. Ph is around 9 and good. But in the Phenalphthalein test, there is a pink color. In fact, there is no excess lye in the formula.
I know that the phenaphthalein test shows the excess lye in the soap. Am I wrong?
Because I drip the phenolphthalene directly onto the potassium hydroxide and the color turns completely pink. I guess this means that phenolphthalein reacts with potassium hydroxide. I test immediately after adding CA to the soap and the pink color is completely gone.
Thank you very much for your reply. You help me a lotSee pages 29-30 of Catherine Failor’s book on Making Liquid Soap.
20% CITRIC ACID SOLUTION - Add after Dilution
Make a 20% solution of citric acid & distilled water:
Add 1 oz. Citric Acid powder to 4 oz. boiling water to make a 20% solution.
Stir until clear. (Can be bottled up and stored at room temp until needed.)
Use Rate: 3/4 oz. (1 1/2 Tablespoons) of solution per pound of paste.
TIP: Never add citric acid powder directly into LS without first diluting it or it can throw the soap out of solution. Warm the batch to 140°F before adding the warmed solution. This may result in “snow flurries” -- white flakes floating in the soap. This can be corrected by stirring and reheating if needed.
That's a sign that the LS paste is not completely saponified, and therefore, not ready for dilution. I would wait 24-48 hours to test again -- or longer if need be. The soap will get there on its own eventually.
While not exactly correct, there is a danger of lowering the pH to a point where the solution "breaks". You don't want that. So take good care when adding the 20% CA solution. Done correctly, you can lower the pH but it's not generally recommended for that reason. There's a good article about testing pH of LS here:
https://alaiynab.blogspot.com/2015/05/ph-testing-of-liquid-soap-and-lowering.html
To correct your current situation:
I would pour off most of the batch while leaving the CA particles in some of diluted LS in a microwave container. Reheat to 159° - 160° F. Stir gently until completely dissolved. To avoid foam, do NOT use a whip or stick blender.
HTH
Yes, it really mixed just fine at 140 F. But I want to try as you said. I'll do a few more tests and wait 2-3 days to wait for the curing to complete. Because I tested the old LS and generally there was no pinking.
What if I dilute a pink paste from the fenophthalein test with water and then wait for it to cure? Is curing complete though?
And my second question, I wanted to do a phenolphthalein test on solid soaps I made 3-4 months ago. I wish I didn't want to test
All my soaps have the same formula, only some with cinnamon, some with lavender and some with tar. I've seen some in pink. However, I use 2% superfat. In some, there was no pinking. Do you think 2% superfat is too low? Would it make more sense to make 5%?
Sorry, but phenolphthalein does not show excess lye; it shows the pH level. It turns pink when you add it to NaOH or KOH because both of those substances have extremely high pH. Likewise, it turns pink when you mix it with liquid soap, because of the high pH of the liquid soap.
If you click the two links I provided in my prior response, you can read two articles, one by @DeeAnna, that explain this very clearly and scientifically.
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Zany_in_CO
Saponifier
As I said earlier, if the paste turns pink when tested, it needs to finish saponification before moving on to the dilution phase. Once you get your head around that you should have the concept down pat. It is confusing.Think about it... there are 3 ways to test whether the paste is ready to dilute or not:
The Soap-in-Water Clarity test
The ZAP test.
Phenolphthalein drops.
In that specific scenario, None of those 3 options are testing pH, or excess lye, or cure. Just whether the paste is fully saponified or not and therefore ready for the Dilution Phase.
Note from my files: Phenolphthalein is an indicator that changes color at a very specific range of pH levels that happens to be perfectly suited for liquid soapmaking.
That is a quote from Steve Mushynsky, Owner of www.summerbeemeadow.com (the first calculator designed for liquid soapmakers) and long-time member of the Liquid Soaping Yahoo Group which is now Defunct. He explains why Phenol P drops work as an indicator of saponifcation in LS. I quote his post in its entirety here for those interested in using Phenolphthalein to test their paste before dilution.
I've been making LS since 2004 and learned from the pioneers (like Steve Mushynsky) on the Yahoo Liquid Soapmaking Group where I was a member for 10 years. From experience, I find Phenol P drops to be the most reliable method to test the paste to make sure it's fully saponified before diluting it.
But that's just me... and I readily admit I'm a little OCD about crystal clear LS.
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Zany_in_CO
Saponifier
Unfortunately, this is the only pic I have of my liquid soap...
Don't you have to add more Lye if you use CA? The CA kills the lye so you have to adjust the amount.
The purpose of adding a citric acid solution to a liquid soap is to neutralize excess lye.
So while you are correct that citric acid does neutralize lye, no, you definitely wouldn't add more lye to a soap that already has excess lye. That would defeat the goal of creating a lye-neutral soap.
Zany_in_CO
Saponifier
Normally, that's correct for hard bars. Liquid Soap is different.
@AliOop is correct as far as neutralizing excess lye. CA is definitely an option if that happens to be the case. However, I prefer using a Borax solution for that.
But CA is also used to slightly lower the pH of the diluted soap before the 2-week Sequester Phase. For example, I made LS for a wholesale customer in NYC. We used her recipe. It included the addition of 20% CA solution (as noted in post #3) to lower the pH to 9.5. Her preference. It supposedly makes the soap milder. I sometimes use it for that reason but I am comfortable with pH 10 or 11 -- which is typical for me.
FWIW, There are about as many ways to make LS as there are LSers. LOL None of the above applies to the most recent variations in circulation. I'm Old School. I learned the basics early on and my LS is crystal clear (my preference) -- just water, oils & KOH at 0%SF -- with nothing extra except for fragrance and color... and sometimes Borax or CA -- just for fun if I'm in the mood.
HTH
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Me tooBut that's just me... and I readily admit I'm a little OCD about crystal clear LS.
That's why I tried maybe 200 or moreAttachments
I wonder how many liters of product did you make with your customer in NYC? And what materials did you use to make the soap? Because it is easy to produce 5-10 liters, but it must be very difficult to produce 200 liters or 500 liters or 1000 liters. Not suitable for producing with pots in the kitchen.
What percentage of essential oil do you use?
I use lemon peel oil at 1% for the Finished LS. But LS has a distinctive smell and sometimes it is more pronounced, so it mixes with essential oil and people with sensitive noses can immediately feel this unpleasant smell. (no problem for smokers
)
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In fact big brands like dr Bronner's often use CA. Because some people's skin is really sensitive. For this reason, it may be important to lower the pH even by 0.5 or 1 point.FWIW, There are about as many ways to make LS as there are LSers. LOL None of the above applies to the most recent variations in circulation. I'm Old School. I learned the basics early on and my LS is crystal clear (my preference) -- just water, oils & KOH at 0%SF -- with nothing extra except for fragrance and color... and sometimes Borax or CA -- just for fun if I'm in the mood.
Zany_in_CO
Saponifier
Awesome! I'm impressed. I did a lot of T & E when I first started making LS but nothing along the well-organized approach you're taking.Me too
Keep up the good work!!!She did shows for the knitting community. I shipped 2L jugs X 4 at a time as needed.
Do you mean D-Limonene? Not my favorite scent but good for cleaning products. I've never had a problem with the odor of LS. I use a variety of blends depending on the customer base and what sells well, i.e., Lavender, Eucalyptus Mint, etc. But that's a subject for another thread.
I rely on MMS fragrance calc to get the rate for EOs. Easy Peasy.
I agree. As it happens, the LS I made for my wholesale customer in NYC was a Dr. Bronner's Baby Mild Castile dupe. Not my recipe but you may enjoy reading this thread:
Dr. Bronner's Copycat LS
HTH
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No, not D-limonen.
did you manage to add CA without changing the color of the soap?
For example, I added about 3% solution with 20% CA solution. The pH was around 9.7. And it went down to around 8.5. but the soap turned white as in the photo.
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Citric acid offers two major advantages. It is a solid soap preservative. It helps reduce soap scum and reduces spoilage and DOS (the dreaded orange stains) in finished soap products. On the other hand, the citric acid reacting with NaOH (with the addition of extra-lye) turns into a chelator that makes the soap usable even in hard water. In cold processing, I mix citric acid (1% ppo) in distilled water until it dissolves completely, after which I pour caustic soda. Only after the composition is completely dissolved and clear, I mix it with the heated oils. So far so good.
Zany_in_CO
Saponifier
That's a first for me. I've never experienced that reaction where the LS goes opaque after adding CA. Your guess is as good as mine as to why that happened. Just think about it for a while and see what you come up with.
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