Sauces, thickening agents, & their functions

Sauces and thickening agents

Thickening agents

To produce great sauces, you must first master the preparation of thickening agents. A sauce must be thick enough to cling lightly to the food; otherwise it will just run off and lie in a puddle on the plate. But this does not mean that it should be heavy and pasty. The following shows how a thickening agent contributes to the structure of a finished sauce.

LIQUID plus THICKEING AGENT makes BASIC SAUCE

BASIC SAUCE plus FLAVORING and SEASONING makes FINISHED SAUCE

Starches as thickeners

Starches are the most common thickening agent. Flour is the principle starch used in sauce making. Other thickening starches include cornstarch, arrowroot, bread crumbs and other vegetable and grain products such as potato starch and rice flour. Starches thicken by gelatinization, the process in which starch granules absorb water and swell to many time to their original size. Acids inhibit gelatinization; do not add acid ingredients to sauces until the starch has fully gelatinized.

Starch granules must be well separated before they are heated in liquid. If the granules are not separated, lumping occurs as the starch on the outside of the lump quickly gelatinizes into a coating and prevents the liquid from reaching the starch inside. You can separate starch granules in two ways.

1. Mix the starch with fat. This is the principle of a roux
2. Mix the starch with a cold liquid. This is the principle used with starches other than flour, such as cornstarch. A mixture of raw starch and cold liquid is called slurry.

The roux

Roux (pronounced “roo”) is a cooked mixture of equal parts (by weight) of fat and flour.

Correct amounts of fat and flour are crucial to a good roux. There must be enough fat to coat all the starch granules, but not too much

A good roux should be stiff, not runny or pourable. A roux with too much fat is called a slack roux. Using excess fat rises to the top of the sauce, where it makes the sauce look greasy unless you skim it off.

Preparing a roux

A roux must be cooked so that the finished sauce does not have the raw, starchy taste of the flour. There are three types of roux, each prepared in a different way.

1. White roux is cooked for just a few minutes-only until the raw taste is cooked out. Stop cooking as soon as the roux has a frothy, chalky, slightly gritty appearance, before it takes on color. White roux is used for béchamel and other white sauces based with milk.
2. Blond roux or pale roux is cooked a little longer, just until the roux begins to take on a slightly darker color. Blond roux is used for veloutes-sauces based on white stocks. These sauces have a pale ivory color.
3. Brown roux is cooked over low heat until it takes on a light brown color and a nutty aroma. Use low heat so that the roux browns easily without scorching. For a deeper brown roux , brown the flour in an oven before adding the fat. A heavily browned roux has only about a third of the thickening power of white roux, but it adds considerable flavor and color to brown sauces.

Incorporating the roux

Combining roux with liquid to obtain a smooth, lump-free sauce is a skill that takes practice to master.

Here are the general principle:

1. Liquid may be added to roux, or roux may be added to liquid
2. The liquid may be hot or cold, but not ice cold. A very cold liquid will solidify the fat in the roux
3. The roux may be warm or cold, but never sizzling hot. Adding a hot liquid to a very hot roux causes splattering and possibly lumps
4. When preparing roux always use a stainless steel sauté pan rather than an aluminum pan because whipping in aluminum causes the roux to turn gray

Other thickening agents (starch-based thickeners)

Beurre manie (burr-mahn-yay)

Is a mixture of equal parts of soft butter or margarine and flour worked together into a smooth paste. Use it for quick thickening at the end of cooking, to finish a sauce. The raw butter or margarine adds flavor and gives sheen to the sauce when it melts. Drop very small pieces into a simmering sauce and stir with a whip until smooth. Repeat until desired consistency is reached. Simmer just a few minutes more to cook the flour and then remove the sauce from the heat.

Whitewash

Is a thin mixture of flour and cold water. Sauces made with whitewash have neither as good a flavor nor as fine a texture as those made with roux

Cornstarch

Has roughly twice the thickening power of flour and produces a sauce that is almost clear, with glossy texture. It is usually used in desserts. Mix cornstarch with cold water until smooth. Stir the mixture into the hot liquid. Bring to a boil and simmer until the liquid turns clear and there is no starchy taste. Do not boil for long, or the starch will break down and the liquid will thin out. Sauces thickened with cornstarch may thin out if held on the steam table for long periods of time.

Arrowroot

Is used like cornstarch and yields an even clearer sauce. It is preferable, but its use is limited by its high cost, which elevates basic food cost

Bread crumbs

And other crumbs will thicken a liquid very quickly because they have already been cooked. Breads crumbs are useful when smoothness of texture is not desired.

The liaison

The liaison, made of egg yolks and cream, is used primarily as a finishing touch to enhance flavor and smoothness of liquids. Egg yolks have the power to thicken a sauce slightly because egg proteins coagulate when heated. Pure egg yolks coagulate very fast; for this reason they are beaten with heavy cream before use. The heavy cream also adds thickness and flavor to the sauce. Use caution when thickening with the egg yolks because of the danger of curdling, which occurs when the proteins coagulate too much and separate from the liquid. Egg yolks have only a slight thickening power. Liaisons produce only slight thickening

REMEMBER: it is only used for finishing technique!!!!

The following are the steps in preparing a liaison:

1. Beat together egg yolks and cream in a stainless steel bowl. Normal proportions are 2 to 3 parts cream and to 1 part egg yolks

2. Very slowly add a little of the hot liquid to the liaison, beating constantly. This is known as tempering.

3. Turn off the heat, add the warmed, diluted liaison to the rest of the sauce, stirring well as you pour it in.

4. Return the sauce to low heat to warm it gently, but do not heat it higher than 180 degrees or it will curdle. NEVER BOIL!

Proportions to roux

Sauce

Butter

Flour

Roux

Liquid

thin or light

6 ounces

6 ounces

12 ounces

1 gal.

Medium

8 ounces

8 ounces

1 pound

1 gal.

Thick or heavy

12 ounces

12 ounces

1-1/2 pounds

1 gal.

Sauces

A sauce is a richly flavored, thickened liquid used to complement another dish. The sauce selected to accompany any dish should heighten it flavor, enhance its appearance, and make it more digestible. It should flow over the food and provide a thin costing, rather than disguise the dish itself. Preparing sauces gives you an opportunity to display your creative and imaginative skills. However there are certain standards that must be met when you prepare a sauce.

The function

Sauces add the following qualities to foods:

1. Moistness

2. Flavor

3. Richness

4. Appearance (color and shine)

5. Interest and appetite appeal

The structure

Sauces are made of three kinds of ingredients:

*A liquid, the body of the sauce

*A thickening agent

*Additional seasoning and flavoring ingredients

The standard

Good sauces meet the following standards of quality:

*consistency and body: smooth with no lumps; not too thick or pasty, but thick enough to coat the food lightly

*flavor: distinctive but well balanced; proper degree of seasoning; no starch taste. The flavor should be selected to enhance or complement the food or to provide a pleasing contrast

*appearance: smooth, with a good shine; good color.

A liquid ingredient provides the body or base of most sauces. There are five basic liquids on which most sauces are built. The five basic types of sauces are called leading sauces

The most frequently used sauces are based on stocks. The quality of these sauces is directly related to the preparation skills of the person making the stocks.

Liquids Leading Sauces

Milk…………………………………………….………….……………….béchamel sauce

White stock…………………………………….……………………………..veloute sauce

Brown stock………………………………….……….…………brown sauce or espagnole

Tomato……………………………………….……………………………….tomato sauce

Butter…………………………………………………………………….hollandaise sauce