@Zink Of the four attributes you’ve listed the emulsifier is a significant factor in only one: stability. For the other three, you are going to add builders to achieve better results (and you are experienced enough to already know that I suspect.) As for emulsifier choice, I’ve never liked the APG family (Montanov) of “naturals” and found better results using the polyglyceryl esters. Co-emulsify with a small amount of anionic such as glyceryl stearate citrate or sodium stearoyl glutamate and you have a nice mild emulsion base without ETO-based nonionics.
Even though I use some Montanov’s….they give me tons of grief! Granted you may not want to use the PEG’s (165 type), that is where I get my best stability, supported with GSC. Sometimes I will include a Montanov in that combo….for added texture to an already stable platform.
I have been doing this a little over two years now….and I have a sunny window….that I put samples in… I use a clear bottle…and fill them only half way….(want tons of head space to aggravate the situation). I have a two year old sample sitting up there…that was just Tego Care PBS 6… (Polyglyceryl-6 Stearate (and) Polyglyceryl-6 Behenate), no co-emulsifier…and probably little or no fatty alcohol. As time goes by…and emulsions break or fail…those samples get tossed….that one still remains. (And the one listed below.)
Oddly enough ( I guess I say that…cuz Lecithin never instilled confidence in my mind….but the other two components shouldn’t surprise.)….the other one that has passed the torture test with flying colors…has been HelioFeel (Glyceryl Stearate Citrate (and) Polyglyceryl-3 Stearate (and) Hydrogenated Lecithin).
So….from someone that early on….with poor combinations (did not use co-emulsifiers or fatty alcohols) and little knowledge, two years ago….Those were standout emulsifiers. Also early on…I tended to use any emulsifier at a very low rate. So I think my tests…speak volumes for those two emulsifiers.
So Matt of course is spot on…I just thought I would give my personal experience, and some brand names you can try and find.