Demi-glace is a classical French brown sauce made by combining espagnole sauce with brown stock and reducing the mixture to a rich, glossy consistency. In the traditional method, equal parts espagnole and brown stock are reduced by about half. Modern kitchens also use the term for a deeply reduced brown stock or jus-style preparation, although the classical sauce and a simple stock reduction are not identical.
Prepare a well-made brown stock and espagnole sauce, combine them in the required proportion and simmer gently while skimming as needed. Reduce until the sauce has a concentrated flavour and enough gelatin and body to coat a spoon. Strain carefully and adjust the final consistency and seasoning. Some recipes finish with Madeira or sherry, but this is not essential to every version.
Demi-glace is used as a base for classical brown sauces and as a finishing component for meat dishes. Derivative sauces may include preparations such as sauce Madeira, chasseur, Robert and other brown sauces, depending on the recipe and culinary tradition.
Brown stock is a liquid prepared from browned bones, vegetables and aromatics. Espagnole is one of the classical French mother sauces, made with brown stock, browned mirepoix and a brown roux, among other ingredients. Demi-glace combines espagnole and brown stock and reduces them to a concentrated sauce.
A finished demi-glace should have a deep brown colour, concentrated flavour and a glossy texture that coats the back of a spoon. Gelatin-rich demi-glace may set to a soft gel when chilled, depending on its concentration.
Chef’s tip: start with a clean, well-made brown stock. Reduction concentrates both good and bad flavours, so burnt bones, bitter aromatics or excessive salt will become more pronounced.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
