Roux - Flour and Fat
A roux is a cooked mixture of about 50 percent sifted bread or all purpose flour (used because of the higher gluten) and clarified fat, usually butter
There are three basic types of roux, each contain the same basic ingredients but differ in coloration which is a result of the cooking process. The darker the roux the longer it has been cooked
White roux used for
velouté (basic white sauce) and some soups
Every roux should be cooked until the taste and acidity of the raw flour is no longer evident.
The amount of roux needed to thicken a soup is about 12 ounces to a gallon and to thicken a sauce about 12 to 15 ounces per gallon.
A rule that must be headed is to never mix a stock and roux together at the same temperature as this will result in lumping or poor quality, All roux sauces must be simmered after the roux is added