Béchamel Sauce for Lasagna

One of the mother sauces of French cuisine, béchamel is a true classic. This simple white sauce is made with milk, butter, and flour, and is the basis of other sauces and used in many recipes, from gratins to macaroni and cheese. We use this silky, creamy béchamel sauce for Lasagna Bolognese, where it holds the layers of pasta together and provides a rich counterpoint to the acidity of the tomatoes.

Any cook who has made a lumpy béchamel knows the pain of seeing the sauce turn clumpy. The secret to success with a béchamel sauce recipe is to cook the roux long enough to avoid a floury taste, and over medium-low heat, being careful not to let it brown. Another tip: whisking constantly while adding flour, then milk, prevents lumps from forming.

What Is Béchamel Sauce? 

A classic French sauce, a béchamel is made with flour, butter, and milk. It is used in many dishes from lasagna to macaroni and cheese to gratins and casseroles to croque monsieur.

The butter and flour are cooked together in a heavy-bottomed saucepan to form a thick paste (the roux) before milk is added. A béchamel uses a white roux, one that has been cooked very quickly to maintain its light color and subtle, nutty flavors. Milk is slowly whisked into the roux and cooked until it takes on a creamy consistency, thickening to the texture required. (Some recipes call for a thick sauce, whereas for use in lasagna, the béchamel needs to have a pourable consistency.) The sauce is then seasoned with salt, pepper, and nutmeg.

Nutmeg in Béchamel

It’s worth mentioning the use of nutmeg in béchamel sauce because you might not notice it. This spice—that you might be familiar with from eggnog or holiday cookies—is a subtle but necessary addition. It brings warmth, spice, and complexity to the blank canvas that is white sauce.

How to Avoid Lumps in a Béchamel Sauce

A lumpy sauce is the last thing you want; follow these simple steps to prevent the sauce from clumping:

• Use warm, not cold, milk (that’s why our recipe calls for heating the milk).
• Add the milk to your roux in increments; this gives the roux chance to accept the liquid evenly. If you add the milk all at once, the roux will seize and create lumps that are difficult to remove.