What affects the PH of soap?

[Ruthie]

I've been reading up on this lately. I've found lots on testing the PH, and even what kinds of strips are most accurate. But I've not found anything about what makes a soap more acid or more alkaline.

In particular I am interested in making a dog shampoo bar and I know that human bars at around 10 on the scale are too acid and not good for dog's skin. What can I do to bring down this number to around 7 to 7.5?

 

[AlchemyandAshes]

I know that human bars at around 10 on the scale are too acid and not good for dog's skin. What can I do to bring down this number to around 7 to 7.5?

You mean "too alkaline", right? Below 7 is acid, above 7 is alkaline.

 

[Ruthie]

You mean "too alkaline", right? Below 7 is acid, above 7 is alkaline.

Glad you understand what I mean, even if it is not what I say.

So far I'm still not finding anything to help in my quest. That is, short of resorting to a syndet. And if I have to do that, why bother?

 

[Lindy]

When you are making a good dog shampoo you need to actually be looking at the qualities of the oils because you have a definitive goal. You want something that is going to condition the skin and coat and not strip it. So like a human shampoo you need to eliminate coconut oil and palm kernel oils. Now let's look at what oils are going to be the most conditioning. You will want olive oil at a reasonable rate, I like to use Tallow in my dog shampoos as well as a lot of castor. From there I have chosen other oils for specific properties. I only use essential oils for scenting and again I am looking at what the properties are because they too have a specific application in the shampoo. Keep your EO total down at 1.5% because of the extra sensitivity dogs have to EO's. If you are creating a cat shampoo - no EO except Valerian because the rest go toxic in cats incredibly fast. With some it can happen with just one exposure because they metabolize everything so much slower and differently. Another good oil for a dog shampoo is Neem oil but keep this down to below 5%, like Lanolin less is more.

Looking forward to following your journey on this.

 

[DeeAnna]

Soap is naturally alkaline, with a pH of 8-10. It's the nature of the beast.

 

[Lindy]

DeeAnna it is, however if you are using the right oils and superfatting correctly then you can create shampoo that does protect the cuticle even though it is alkaline. You can't take just any old bar of soap and call it shampoo or you are going to have problems plus need the cider vinegar rinse. Plus with research you are going to find additives that actually make a superior shampoo.

 

[justinwp]

Soap becomes 'not soap' at anything much below 9 and a dog's skin is more alkaline than humans. It just cannot handle being stripped of its natural protective layers as easily as ours can. Your best bet is to simply create the most gentle bar you can formulate.

 

[DeeAnna]

DeeAnna it is, however if you are using the right oils and superfatting correctly then you can create shampoo that does protect the cuticle even though it is alkaline....

You make a good point, Lindy! Thanks for the explanation. I've been following your original thread about shampoo bars and agree with your point of view -- the shampoo bars I've made based on your recommendations are working very well for me.

I was responding specifically to Ruthie's question "...What can I do to bring down this [pH] number to around 7 to 7.5?..." I was just wanting to point out that if it's true soap, the pH is naturally alkaline -- I don't think a lot of people realize that.

I think the broader (and more useful) answer to her question is the info you've offered, however.

 

[Lindy]

DeeAnna thank you for clarifying - I took your answer at face value rather than thinking more deeply about it. I have heard of people adding some baking soda and/or citric acid to lower pH but you have to be so careful because you can break the reaction of the soap and turn it into something else (sludge comes to mind here)