Demi-glace

Demi-glace (English: "half glaze") is a rich brown sauce in French cuisine used by itself or as a base for other sauces. The term comes from the French word glace, which, used in reference to a sauce, means icing or glaze. It is traditionally made by combining equal parts of veal stock and espagnole sauce, the latter being one of the five mother sauces of classical French cuisine, and the mixture is then simmered and reduced by half.

Common variants of demi-glace use a 1:1 mixture of beef or chicken stock to sauce espagnole; these are referred to as "beef demi-glace" (demi-glace au boeuf) or "chicken demi-glace" (demi-glace au poulet). The term "demi-glace" by itself implies that it is made with the traditional veal stock.

Preparation

The basic recipe for demi-glace is provided by the French chef Auguste Escoffier, who is often considered to have established the method of French cooking as well as codified many of the standard French recipes. Although many recipes for demi-glace give the preparation for the espagnole first, and then the recipe for the brown stock, preparation should actually proceed in the reverse.