This common white sauce uses roux to thicken milk or cream. The roux is cooked for about 3 minutes to keep it "white." For lump free sauce, remove the roux from the heat before stirring in the milk. Warm the milk in the microwave before adding to the roux. This will spare the muscles in your hand, as you won't have to stir the sauce so long before it comes to a boil. Use a whisk to incorporate the milk into the roux and stir until it is lump free. Return to the heat source and bring to a boil.
Home cookbooks say to just boil the sauce for 1 minute to cook out the flour flavor. Professional cookbooks encourage you to reduce the heat after bringing the sauce to a boil, then continue to simmer the sauce for 15-30 minutes, stirring, to remove the flour taste. What you actually do will depend upon your time limit and personal tastes.
If your sauce is lumpy after your best efforts, you possibly didn't beat it enough before cooking, brought it to a boil too quickly, or didn't stir it enough during cooking so that it stuck to the pan bottom. To repair, pour it through a strainer or process the sauce in a blender. Return the strained or blended sauce to a clean pan and heat to the boiling point.
The recipe below makes white sauce of medium thickness. For a thinner sauce, use 1 tablespoon butter to 1 tablespoon flour. For a thicker sauce, use 3-4 tablespoons butter to 3-4 tablespoons flour. Click here for variations on this sauce. Béchamel can be stored in the refrigerator for up to 1 week.
Béchamel (Basic White) Makes 1 cup
2 tablespoons flour
1/2 teaspoon salt
1/8 teaspoon pepper
1 cup milk, warm
Melt butter in a saucepan over low heat. Blend in flour, salt, and pepper. Cook over low heat, stirring until mixture is smooth and bubbly. This is called a white roux. Remove from heat. Stir in warm milk and whisk until mixture is smooth and lump-free. Return to heat. Bring to a boil, stirring constantly. Boil for at least one minute.