Yesterday, Dennis sent me the following email.

"....have questions about your soap. do you/how do you/ check the pH of the final product? i have done a side by side compare of one of your soaps (cranberry almond) and "dove" and find your soap can sting a little bit more on sensitive skin. on the other face jackie says your barnone soap leaves her face quite smooth and less dry than the other face soaps (cetaphil)."

Good question.

A few words about pH.
I use standard pH testing strips to test my soaps. At first I was testing my soaps only after they had either cured (for cold process soap) or cooked (for hot process soap). My soaps always seemed to test at a pH of 8, so I started testing them during the various soapmaking stages just for the sake of curiousity and I determined that my soaps will tend to test at pH 8 as soon as all the oils are saponified. Sorry for the blurry photo. The camera wouldn't focus on the tiny bottle of test strips but there they are.

Saponification: The chemical reaction between lye (or alkali) and fats (or oils), yielding soap and glycerin as the products of the reaction.

A good part of saponification takes place during the combination of the oils and lye water in the soap pot. The oil is first heated to the desired temperature and once the lye water is added, no further heating is needed. The chemical reaction of saponification proceeds and generates sufficient heat for the soap to thicken (brought to trace) and is ready to be poured into molds to solidify. Trace is helped along by the fact that I use an immersion blender that I purchased specifically for this duty. Any further saponification needing to occur happens after the soap is poured into the mold and is insulated and let to sit. I usually let it rest overnight. The soap, while insulated in the mold, goes through a gel phase whereas the soap generates enough heat that starting at the center of the soap loaf, the thickened soap turns gel-like and then this gel-like reaction radiates outwards until the soap loaf cools and solidifies. You can actually feel the heat coming from the mold when the soap is gelin'.

This means that in the case of cold processed soap, unless I do something really radical, my soap will test at a pH of 8 as soon as it is ready to be unmolded and cut into bars. With hot process, the soap is 'cooked' after it has thickened in the soap pot (whether it be in the oven, crockpot or dutch oven on the stove) and the gel phase occurs during cooking. The cooking also forces the soap to harden or cure faster because the applied heat forces evaporation of excess water and moisture. So as soon as it's done cooking, again, pH of 8.

With all my soaps testing at the magical number of 8, I questioned the accuracy of my pH strips. So I tested lye water and it tested at 14. I tested the unsaponified lye water and oils together, again - bad juju. So I guess my strips are good.

The idea that my soap would be neutral within days of my making it really had me in a state of disbelief. With all the research that I had done, I was led to believe that soap would reach a neutral state only AFTER it had cured. Most sources state that cure time equals 4 weeks. This is why I ran so many pH tests at the beginning. So basically, now I run a pH test after I cut the soap into bars. If it tests at 8, then I still won't release the soap for use until a few weeks down the road just to make sure the bars have hardened enough. If the pH doesn't test where I want it, I will retest the bars throughout the 'cure' process.

More interesting stuff about pH.
Here's an interesting site that talks about pH in regard to soapmaking. http://waltonfeed.com/old/soap/soaplit.html

The site lists the following brands of soap and their pH.
Camay 9.5
Dial 9.5
Dove 7.0
Irish Spring 9.5
Ivory 9.5
Lever 2000 9.0
Palmolive 10.0
Zest 10.0

I do not know where this information is obtained (if the author tested the soap himself or not) but if it is correct, then it sure is interesting. The site also claims the following:

"Soapmakers in general say they shun soaps with a pH over 9 but look at the major brands! Notice the Dove above... a true neutral pH soap. To get this you'd have to run your cured soap through a rebatch operation and mix in boric acid to lower the soap's naturally high pH. My cured soaps now weigh in anywhere between a pH of 9 to 10. I've also thrown a pH strip to a couple of other soapmaker's soaps sold on the internet and find they also come in at about the same pH as mine."

If this is accurate then gee... my soap IS really good stuff! :)

A few words about sensitivity.
Most people that are sensitive or allergic to soaps and other products applied to the skin are 'allergic' to the colorants and/or the fragrances that are in the product. Some people are okay with some fragrance oils and not others. Some folks are fine with essential oils, but not fragrance oils. And some are okay with a degree of fragrance, but not too much.

Although all of my ingredients - base oils, essential oils, fragrance oils, and colorants are top-notch, are specifically designed for soapmaking, and have been tested to be safe for use on skin, that doesn't guarantee that individuals won't have a reaction. Hopefully it doesn't happen often though.

In the case of my Cranberry Almond soap, I used both colorant and fragrance oils. I used very little coloring so I'm betting that the stinging you have experienced is probably due to the fragrance oils. I used both a cranberry fragrance oil and an amaretto one. You might have a sensitivity to one or both of them. That doesn't mean that you will be sensitive to other fragrances of the same name by other suppliers though. It also could have been the amount of fragrance that I used, although I didn't use an awful lot in that soap. You might want to see if any of the other soaps I've given Jackie give you the same sort of sting. Regardless, we can keep narrowing it down to try and figure out what it is you're sensitive to and we can always make changes or come up with something else for you.

I'm glad to hear that the Bar None soap is working well for Jackie. Since there are no fragrances or colorants in it, it should be great for sensitive skin. Have you tried that one yet?

I added a couple of comments to the Bar None post. I looked up the ingredients of Cetaphil. Interesting stuff. For those that are curious, go to the comment section of Bar None and check it out.