thickens about a quart (liter) or 4 servings of soup. It doesn't thicken it so drastically that you

need a knife and fork to eat it, but it does add a light body.

Chinese cooks sometimes thicken soups by adding whole eggs. For egg drop soup, for

example, you first thoroughly scramble whole eggs, and pour them into the hot soup in a

slow, steady stream without stirring. The instantly-cooked eggs provide a body that doesn't

really thicken the liquid but gives the soup an altogether different consistency and feel.

Asian cooks also use cornstarch as common thickener. They use it more in stir fries and

sauces, but occasionally for soups, too. To do so, dissolve the cornstarch in cold water, stir it

into the hot soup and cook for a few seconds until thickened. Cornstarch only thickens liquid,

it doesn't add flavor or any extra chunks, but if you do a poor job of dissolving it in cold

water, you get the dreaded lumps. The proportions are 1½ tablespoons cornstarch in 3

tablespoons cold water for a quart (liter) of soup. You may use other root starches, such as

tapioca and arrowroot or even plain flour (see discussion of starches, under Desserts).

In French cooking, and in the New Orleans cuisine, chefs favorite thickener is the roux. Any

cuisine with strong French influence also has roux at hand at all times. Roux thickens sauces,

creamed vegetables, even stews, but is also great for soups. It is simple, effective and adds a

hint of new flavor to the thickened dish.

How to thicken with roux

Roux is simply a cooked mixture of fat and flour in about equal proportions. There are

three types: white, blond and brown (chefs also label them as light, medium and dark). You

prepare all three the same way over heat but remove them from heat at different stages. You

cook white roux for just a few minutes until the flour barely begins to color but has lost its raw

taste. This is good for light sauces, delicate soups and creamed vegetables. Blond roux you cook

longer, until the flour turns a light beige, the color of croissant. It is best for more robust sauces

and hearty, flavor-rich soups. In brown roux you allow the flour to darken even more to the color

of pumpernickel and you use it mainly for robust gravies and sauces, real hearty soups.

Cajun cooks use an even darker roux—almost black, the color of a dark bittersweet

chocolate. To do this, add oil to a very hot skillet, dump in the flour and with vigorous stirring

make the roux that blackens in seconds. In such a very hot skillet the starch granules damage

enough so they lose their thickening power. However, the browning reaction and caramelization

develop great new flavors. This sort of roux is not to thicken but to enhance flavor.

Roux contributes flavor, owing to the partially cooked flour, in addition to its thickening

power. The longer you brown the flour, the less its thickening ability. For the same degree of

thickening, you need more brown roux than blond or white roux.

A neat professional trick is to use two different types of roux in the same dish—dark roux

for flavor and light roux for thickening. In French and Cajun cooking prepared roux of all types

is always by the stove so in their kitchen it is easy to blend two types. The home cook usually

has no such ready access.

You can mix butter or oil or a combination of these two with flour to make any of the

three roux. For extra flavor in subtle soups, butter is best. In an already rich soup, the butter

flavor is so overwhelmed you might as well use oil. Cajun cooking uses lard for real richness and

plenty of flavor. It also uses roasted meat or bacon drippings but these mostly in roux for

thickening sauces.

To make a roux, cook the flour and fat over low to medium heat, stirring continuously.

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