Hmm, suspect vodka is denaturing proteins just by being high enough alcohol content, not necessarily by being acidic (ETA were you around that time I was reading up on exactly how alcoholic you can make jello shots before they refuse to set?). Did search for pH of liqueurs, thought that might be more useful than "acidity" since acidity is used a lot in flavor profile of wines and that was skewing the results, but apparently just no one talks about the pH of various alcohols.

*hugs you*