How to Make Modernist Vinaigrette?

I don't know if this counts as particularly modernist, but if the main criteria is to keep the dressing from separating, it can be done with a few drops of liquid lecithin.

Many traditional recipes call for mustard, egg yolk, or even a bit of store bought mayonnaise to hold dressings together, all of which have some form of emulsifier (and in the case of store mayo is probably just pure soy lecithin).

Just buying liquid lecithin (available online pretty easily) skips right to the heart of things. It is used in fancier emulsifications in modernist techniques, but can be used very simply in a vinaigrette. A few drops will do ya.

One of the joys of modernist cooking is being able to mix unlike ingredients together and vinaigrettes are perfect examples of this. I also enjoy not having to keep shaking my dressing each time I use it! Basically, vinaigrettes are made through the process of emulsification. Initially, this will blend together as it is whisked, but will eventually break apart from each other because of its natural properties. The best way to keep ingredients together is to stabilize your vinaigrette emulsion.

Stabilizing can be done by thickening your already made dressing with a thickener. There are a number of different thickeners, but I prefer to use xanthan gum. Another option for stabilizing an emulsion is to strengthen it by adding an emulsifier. Like thickeners, there are a few different kinds that can be used but I personally prefer mono and diglycerides as well as lecithin.

The process for both is easy. All you need to do is blend in the thickener or emulsifier to the prepared vinaigrette. I like to make sure that the dressing is seasoned before stabilizing it. Also, I would use a blender or other high power tool for blending since the amount of force used is often a key to emulsifying substances.