Sauces are thickened liquids which may be savory or sweet and hot, warm or cold according to type and purpose. They may be served with or as an accompaniment to a wide variety of dishes with the intention of contrasting or complementing the flavor and texture of the items with which they are served, aiding the digestion of the main dish or enhancing its appearance. The range of flavors is considerable, from the most delicate to the very rich and distinctive, and can vary in cost from the inexpensive to the almost prohibitive. Whatever their function, the importance attached to sauces should never be underestimated.
As sauces play such an important and significant part in cookery the caterer must fully understand the basic principles involved in preparing a quality sauce, and be able to rectify any of the many faults which frequently occur in their preparation. He must also be familiar with their many uses and be able to evaluate them in an objective and professional manner.
The principal thickening agent used in a wide range of sauces is a cooked mixture of flour and fat known as a roux. There are three types of roux:
(a) white roux (roux blanc), also known as a first stage roux;
(b) fawn roux (roux blond), also known as a second stage roux;
(c) brown roux (roux brun), also known as a third stage roux.
The degree to which a roux is cooked determines its color which in turn affects the color and flavor of the sauce that is made from it.
Other thickening agents (also known as liaisons) used in the preparation of sauces include the following:
(c) potato flour or other starch;
(e) a mixture of flour and fat;
(8) egg yolks;
(i) mixture of egg yolks and cream;
(k) blood (as in jugged jare).