I noticed also, now i'm at my computer, that you linked Swift Crafty Monkey's blog on preservatives. In the Q&A at the bottom of the blog, a question was asked in regards to soaps, and here is that exerpt:
" Kathy said... Susan - I just started making liquid soap, and the formulators and blogs all state that the resulting pH in liquid soap is around 9.5-10 so you don't need to add a preservative? Correct or no?
PS - I'm really hoping that someday you do a series on liquid or cream soap making. Thanks.
January 29, 2012 at 11:07 PM"
with the bloggers answer being....
"
Susan Barclay-Nichols said... Hi Kathy! I'm not talking about soap (as defined as being a product that is saponified by adding lye to oils and creating soap...not syndet bars!) when it comes to preservatives. Just the things that have a pH of 8 or lower.
Which doesn't mean that one can raise the pH of your body wash, shampoo, and so on to 8 to avoid using preservatives!
January 30, 2012 at 6:24 AM "
Susan, the blogger, distinctly says she was referring to other wter based products needing a preservative, ie lotions and conditioners. Susan also reaffirmed my stance on pH inhibiting microbial growth. Sadly enough a few comments down, she flat out admits she knows NOTHING about soap making.
In the first link you referenced, LaShonda, the blogger, made an interesting comment:
"
Test Your Product: Send your preserved or even your un-preserved liquid soap to be microbial tested. This way you will know if when you are preserving your product that you are preserving at a level that is sufficient. Please keep in mind that
no product will be 100% bacteria free but there are level of microbials that become unsafe."
Is she speaking in terms of evidence based fact, or is this her own opinion? A comment like this would make me wonder, what's the point then? You can only use a certain max level of preservative that is considered safe in any one product, but if that doesn't cut it, why bother? It leaves more room for debate, and confusion, on a topic that is already highly so on both counts.