Emulsified Sauces (I) : cohabitation between two ennemies...

An emulsion is a good example of cohabitation between two ingredients which usually can stand each other. It is a stable distribution of microscopic droplets of one liquid into another with which is would not mix normally. Huile (oil) and Vinaigre (vinegar) are the obvious example in Cooking.

Nevertheless, stabilisation needs a third part : an emulsifying agent. Most of the time, it is the Jaune d'Oeuf (egg yolk). Egg yolk has two major qualities : it is lipophilic (affinity with fat) and also hydrophilic (affinity with water) which makes of it a very good friend for every sauce (basic or derivated). It is also very powerful : one single egg yolk can bind between 150 ml and 200 ml !!!.

This agent is used for warm emulsified sauces (e.g. Sauce Bearnaise) and cold emulsified sauces (e.g.Sauce Mayonnaise).