>>819
>I know it lets them mix together but is that what actually causes mayonnaise to congeal into a thick cream?
Short answer: Yes.
Long answer: So as you said, the egg yolk is the emulsifier in this recipe, hence allowing the oil and water to mix together. Essentially, when you're mixing the two, you want the oil droplets suspended in the water, and the emulsifier allows for this to happen since naturally, the two would just separate. This has to do with the nature of the emulsifier, consisting of a hydrophobic (hates water) and hydrophilic (loves water) side. Fun fact: This is the same thing happening with detergents (like soap) and water which leads to bubbles. This emulsification is what leads to the mayonnaise congealing into a thick cream, assuming you use a high-powered device like a food processor or blender. If you whisked your mayonnaise, you'd end up with something that looks less white and creamy and more yellow and saucy. The reason is that the bubbles suspended are larger compared to when you blend the hell out of it. Blending leads to smaller oil droplets and thus, a more creamy mayonnaise. Of course, you need to do this slowly or the mayonnaise can break, but anyway, that's another issue.
>I realized the raw egg yolk would be a health concern so I'm assuming mayonnaise uses acids to sterilize (?) and kill bacteria, much the same way vinegar and shit works in like pickling. Is that accurate to say?
I actually wasn't sure myself, so I looked it up. According to the USDA (
https://ask.usda.gov/s/article/Is-homemade-mayonnaise-safe), it isn't safe to consume mayonnaise because it consists of raw egg. However, looking elsewhere (
https://www.epicurious.com/ingredients/the-truth-about-mayonnaise-and-food-safety-article), it seems the acidity is what prevents bacteria from flourishing in your mayonnaise, so sterilising in a way. However, the website I read seemed to suggest that commercially-sold mayonnaise is safe no matter what, but homemade must be kept cold. I guess if you're immune-suppressant and never taste your raw cake batter, homemade mayonnaise should be avoided. But somehow I doubt anyone really catches salmonella from mayonnaise.