The Roux

The various kinds of Roux are used as the thickening agents for basic sauces, and their preparation, which appears to be of little importance, should actually be carried out with a great deal of care and attention. Three kinds of Roux are used—brown Roux for brown sauces, blond Roux for Veloutés and cream sauces and white Roux for Béchamel and white sauces. In large kitchens brown Roux is usually made in advance; blond and white Roux are made as required. The time necessary for the cooking of Roux depends upon the intensity of the heat being applied and cannot be determined mathematically. It is advisable to cook it slowly rather than too quickly as the application of a fierce heat will cause the starch granules to harden. This will constrict the contents of the starch granules and prevent them from combining with the liquid when added to form the sauce. In this case it produces an analogy with that which takes place when cooking pulses in boiling water. It is necessary to start with a moderate heat, increasing it progressively so as to allow the outer coating of the starch granules to distend, thus allowing the starch which they contain to swell and, under the influence of the heat, to break down, transforming it into dextrin, a soluble substance which is involved in the thickening process.