Egg Yolks as Binding Agent

Egg yolks bind as they coagulate. As the proteins link together, they trap other solids (such as milk solids) and, in so doing, thicken sauces or set custards. Sauces, such as crème Anglaise and Hollandaise sauce, and set custards, such as crème brûlée and crème caramel, all rely on egg yolks to reach their desired consistency. Egg yolks can also thicken velouté sauces such as a bâtarde or allemande sauce. In cooking, a binder is called a liaison.