Checking ph in CP - what's the best way?

[clhigh29]

I don't sell because I'm still in my first year of making soap. Everyone who uses my soap loves it, so I'm troubled by two recent reports of skin irritation. I, too, have noticed that my hands are a bit drier than usual (although my son says the exact opposite about his). I run everything through soapcalc and have been superfatting at 5%. My oils are basic ... olive, coconut, palm, avocado, castor, and shea or mango butter, nothing exotic. My husband recently developed some redness on his knuckles, and someone else who likes my lavender soap had rashes on his body that would appear, then clear up all while using my soap.

Maybe it's not the soap at all, but I wondered what is the best way to check the ph. I freaked out this morning when I used some phenolphthalein on every one of my soaps (as well as one I got from a soap swap), and they all turned bright pink when I rinsed them under water. I decided that this was not the best way to check, since it would be impossible for all these soaps to be bad. Then I tried the zap test, and nothing seemed to stand out. They all tasted like soap. I almost thought I was imagining a zap, so I asked my husband to try one, and he got nothing. The soaps all look like nice ... no crystals or lye rivers.

So I was wondering if anyone checks the ph in their soap regularly, and what is the best method for doing so. I'd like to do this regularly so that I can be more confident about my product.

Thanks in advance for the help.

 

[DeeAnna]

Testing pH of soap is controversial. There are frequent and recent discussions on this issue:

https://www.google.com/search?q=ph+soap+site:soapmakingforum.com
Also http://www.soapmakingforum.com/showthread.php?t=43328

If you have questions after skimming through these threads, I'm sure someone(s) will chime in to help.

 

[FlybyStardancer]

Phenolphthalein isn't the best way to test soap, especially bar soaps!

As far as some irritation... Maybe the coconut oil percentage is too high for 5% superfat for you? I'm thinking mine might be, and I'm using 20% at a 6% SF. Some people can't handle coconut at all.

 

[clhigh29]

Thanks for your input. Deanna, I'm going to read those links as soon as I'm able. Flybystardancer, I think most of my recipes are 20% coconut oil. But why now might it be an issue? I would just love to be able to test my soap with a quick, reliable method before giving it. Nothing worse than someone thinking your soap is causing them problems.

 

[coffeetime]

There are lots of possibilities: what percentage of EO or FO, what are you using for colourants, has your husband tried any of your other formulas? Did he react to those? What is the difference? I find some people are sensitive to different oils. I find a high percentage olive oil soap drying until it has cured 4-6 months.

Some more info on ingredients would help us help you.

 

[clhigh29]

I've been asking the same questions. I think my husband might have issues with eucalyptus. My remaining concern is the lavender soap. The only thing I did differently from the first batch to the second that might be causing a problem is that I made lavender water (instead of regular water), and I changed lye from BB flakes to 100% lye pellets. That loaf is the only time I ever experienced overheating. I made one batch before the lavender that is amazing with the same ingredients (different fragrance) and didn't overheat. I love it so much I hate to give it away.

 

[Susie]

I still zap test my bar soaps. If I were you, just to test everyone at once, is to make a batch with no more than 20% coconut oil, 5% SF, no EOs and no colorants. Have everyone who has complained of itching/irritation swap to that for 2 weeks straight (when it is ready). Have them change nothing else in their lives-no new laundry detergent, no new dryer sheets, no new foods, etc. Then, and only then, can you tell if it is your soap, or one of 1000 other possibilities.

 

[DeeAnna]

As others have pointed out, there are a huge number of factors that can cause or aggravate skin irritation. If a soap is causing irritation from excess alkalinity (lye heavy) or from some ingredient in the soap recipe (coconut oil, shea butter, fragrance, etc.), then continuing to use the soap will only make matters worse, not better. I honestly wouldn't expect a rash or irritation to happen and then go away, all the while continuing to use the offending product.

For example, the irritation on your husband's knuckles could very likely be from a solvent or grease or other product that he used for, say, doing maintenance on the car. Or it could be dryness and irritation aggravated by the long hard winter we've all endured in the northern US. A guy I used to know was getting a mysterious irritation on his fingers complete with redness, itchiness, and peeling skin. He eventually traced to a solvent he occasionally used to clean electrical contacts.

And it doesn't have to be a new product to cause problems -- people can become sensitive to products they have been using for years.

 

[clhigh29]

Aha! Deanna, you may be on to something. My husband is convinced it's the lye, but he continues to the use my soap, and his hand have cleared up. He suspects it was the eucalyptus soap, which I have a difficult time accepting since it's loaded with shea butter and avocado oil, and I've used it myself with no issues. However, he has also recently taken out his fishing equipment, so there may have been something in his tackle box that irritated his hands. I also thought it was strange that my lavender-loving friend would have rashes come and go as he worked his way through three bars of soap. I didn't want to be in denial, because if it is my soap, I wanted to be able to check the ph to be certain. But I suppose there is no accurate method for doing so; therefore, zap testing will continue, and if someone suspects my soap, they'll have to discontinue using it :sad:

 

[DeeAnna]

Well, if you've waded through a few of the posts about pH that I referenced (especially the last one), you'll know the pH of a properly made soap will vary depending on the fatty acids involved. So even if you knew the pH within a tenth of a point, you still would not know for sure if the soap had excess alkalinity -- aka "too much lye" or "lye heavy".

Excess alkalinity is really what you're wondering about, not pH. The zap test is an indicator of alkalinity. The only other way I know of to determine alkalinity is a chemistry lab test -- dissolve a sample of soap dissolved in water and titrate the soap solution with an acid.

The effects of a lye heavy soap are hard to ignore -- it causes intense itching/burning and sometimes some redness. The irritation happens shortly after use. (Don't ask me how I know that :eh: )

I still think it's odd that folks are getting irritations or rashes that are resolving themselves, all while using your soap. That just doesn't point to the soap as the problem, in my opinion. (Caveats -- some people are sensitive to shea, I understand. If one is allergic to latex, I gather shea may also trigger an allergic reaction. And coconut oil irritates the skin of some people.)

But I'm not a dermatologist, so I'm just an amateur doing armchair medicine. YMMV and all that!

 

[The Efficacious Gentleman]

...........If one is allergic to latex, I gather shea may also trigger an allergic reaction.....................

Slightly off topic, but the people who I was thinking of when I made my Castile have latex allergies, but we weren't sure about shea - I think we'll play it safe! Thanks, DeeAnna.

Back on topic, one thing I was meaning to ask was:

Can a soap be lye heavy and still have a relatively low pH? We know from the charts that there are soaps that are not lye heavy which have a pH over 12, but in theory could one end up with a lye-heavy soap but with a pH lower than 12? Or would the remaining lye push the pH reading up much more?

 

[DeeAnna]

Yes, in theory, one could have a lye-heavy soap with a pH under 12. Check the tables I posted here: http://www.soapmakingforum.com/showpost.php?p=414542&postcount=22

I am cringing about getting into another endless debate about pH again, so I'm going to leave it at this.

 

[The Efficacious Gentleman]

I think it's a good idea. I see the thread titles and take a deep breath before clicking. But thanks for confirming the above for me - very worrying for those who go on pH alone.

 

[DeeAnna]

Thanks, Gent. I appreciate your thoughtfulness.