That’s probably the safest bet- you can accurately control the temperature and time. And you could I suppose, pasteurize your vinegar/lemon juice and oil as well if you felt like it.
Regarding shelf stability and refrigeration of mayo: The packaged mayo is shelf stable prior to opening because it is packaged with mostly nitrogen in the head space. Once opened, the oil oxidizes as it is exposed to air. Oxidized oil does not taste good, but is not dangerous. Refrigeration slows the oxidation.
That’s how I remember it when I worked on Hellmann’s.
Thank you for your service.
And I’ll bet you used pasteurized eggs for sure as well, to dramatically reduce the bacterial presence within the finished mayonnaise.
Yes, we got an egg/spice mixture to our specifications that used pasteurized eggs. We weren’t in the business of cracking eggs in the plant.
We had a lot of methods for bacterial control, most in the formulation. Mostly salt and acid. Obviously, keep the plant clean keeps most issues away.