Classical demiglace
Source of Recipe
???
Recipe Introduction
Time of cooking will vary depending on how fast you reduce the sauce. It is best to do it slowly.
List of Ingredients
1 quart brown stock (veal or beef)
1 quart espagnole sauce
Recipe
Reduce the stock by 1/3.
Add the sauce Espagnole and reduce until you're left with one quart.
Strain the sauce through cheesecloth.