Ingredient Proportions

The traditional proportions of fat and flour in a roux is equal parts by weight or, in other words, 50 percent fat and 50 percent flour. Many chefs use a lower proportion of fat. There must be enough fat to coat all the starch granules, but not too much. A good roux is stiff, not runny or pourable. A roux with too much fat is called a slack roux. Excess fat increases the cost of the roux unnecessarily. The excess fat rises to the top of the sauce, where it is either skimmed off or makes the sauce look greasy.