Q&A: Which preservative works best with alkaline liquid soap? Let’s talk about the chemistry of soap, pH, and preservatives!

In the June Q&A, smc asked, Preservatives for liquid soap. I’m playing with liquid soap make, and due to the high percentage of water I’ll need a preservative. What preservatives work well in a high pH environment and doesn’t have a horrible scent? Thanks.  As a quick note before we start, I have pages where…