What is demi-glace and how is it typically produced?

• A. A light vinaigrette reduction.
• B. A rich glaze made by reducing Espagnole with stock (often veal/beef) until it coats the back of a spoon.
• C. A stock used directly without reduction.
• D. A sauce made by emulsifying butter into tomato sauce.

Answer: (B)

Demi-glace is a rich glaze used as a finishing sauce, formed by reducing a brown sauce with stock until it thickens enough to coat the back of a spoon. It’s typically made by starting with Espagnole (the brown sauce) and adding stock, then simmering slowly to concentrate flavors and achieve a glossy, velvety texture. This reduction creates a deeply flavored foundation that can be used as-is or as a base for many other sauces for meats.

It isn’t a light vinaigrette reduction, nor simply a stock used without reduction, nor a sauce made by emulsifying butter into tomato sauce. Those options describe different preparations, whereas demi-glace specifically refers to the browned-sauce reduction (Espagnole plus stock) that yields a rich glaze.