A good white sauce for lasagna is just butter, flour and milk, cooked for about 10 minutes. It makes the layers creamy instead of dry, and it is the sauce behind every white lasagna and every lasagna bianca. This version makes about 3 cups, which is enough for a 9×13 inch pan.
It is the same method as my classic béchamel sauce, with a few changes that matter specifically for lasagna: how thick it should be, how much you need, and how to make it ahead.
Ingredients for White Sauce for Lasagna
- 4 tablespoons (55 g) unsalted butter
- 1/4 cup (30 g) all-purpose flour
- 3 cups (720 ml) whole milk, warmed
- 1/2 teaspoon salt
- A pinch of nutmeg
- White or black pepper, to taste
How to Make White Sauce for Lasagna
- Warm the milk. Heat it in the microwave or a small pot until warm, not boiling. Warm milk blends into the roux with far fewer lumps.
- Make the roux. Melt the butter over medium-low heat. Add the flour and whisk for 1 to 2 minutes, until it smells slightly nutty but has not taken on color.
- Add the milk slowly. Pour in about 1/2 cup first and whisk until smooth, then add the rest in a steady stream while whisking.
- Simmer. Cook for 5 to 8 minutes, stirring often, until the sauce coats the back of a spoon.
- Season. Stir in the salt, nutmeg and pepper. Taste and adjust.
How Thick Should White Sauce Be for Lasagna?
Pourable, like heavy cream. It should coat a spoon but still run off it easily. Noodles absorb liquid as they bake, so a sauce that is as thick as pudding turns heavy and pasty in the oven. If it gets too thick, whisk in a splash of warm milk.
How to Use It in Lasagna
Spread a thin layer of sauce on the bottom of the dish so the noodles do not stick. Then alternate noodles, sauce, your filling (cooked chicken, sautéed spinach, mushrooms or sausage) and mozzarella. Finish with sauce and cheese on top. Bake at 375°F (190°C), covered, for about 30 minutes, then uncovered for 10 to 15 minutes until golden and bubbling. Let it rest 10 minutes before cutting.
My favorite version is chicken and spinach with a little Parmesan stirred into the sauce. I cook the spinach first and squeeze out the water, otherwise the layers turn soupy.
How to Fix Lumpy White Sauce
Whisk hard off the heat. If lumps remain, pour the sauce through a fine sieve or blend it for a few seconds with an immersion blender. It will be smooth again.
White Sauce Variations
- Cheesy: stir in 1/2 cup grated Parmesan or Gruyère off the heat. That turns it into a Mornay sauce, which is richer and great for white lasagna.
- Garlic: cook 2 minced garlic cloves in the butter for 30 seconds before adding the flour.
- Lighter: use 2% milk. The sauce will be a little less rich but still works.
Béchamel, Mornay and Velouté: What Is the Difference?
All three start from a roux. Béchamel uses milk. Velouté uses a light stock (chicken, fish or veal) instead of milk. Mornay is béchamel with cheese added. For lasagna, béchamel or Mornay is what you want. If you like the lasagna idea in soup form, try my lasagna soup.
Make Ahead and Storage
Press plastic wrap directly on the surface so no skin forms, then refrigerate for up to 3 days. It will set firm. Warm it gently with a splash of milk and whisk until smooth before assembling the lasagna. For leftovers, store the baked lasagna in the fridge for up to 4 days, in line with the USDA’s guidance on leftovers and food safety.
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White Sauce for Lasagna (Easy Béchamel in 10 Minutes)
- Total Time: 15 minutes
- Yield: 3 cups 1x
Description
Smooth, creamy béchamel made with butter, flour and milk in about 10 minutes. Enough for a 9×13 inch lasagna.
Ingredients
- 4 tablespoons (55 g) unsalted butter
- 1/4 cup (30 g) all-purpose flour
- 3 cups (720 ml) whole milk, warmed
- 1/2 teaspoon salt
- 1 pinch nutmeg
- White or black pepper, to taste
Instructions
- Warm the milk in the microwave or a small pot until warm, not boiling.
- Melt the butter over medium-low heat. Add the flour and whisk for 1 to 2 minutes, until it smells slightly nutty but has not taken on color.
- Add about 1/2 cup of milk and whisk until smooth, then pour in the rest in a steady stream while whisking.
- Simmer for 5 to 8 minutes, stirring often, until the sauce coats the back of a spoon.
- Stir in the salt, nutmeg and pepper. Taste and adjust.
Notes
The sauce should be pourable, like heavy cream. Store covered with plastic wrap pressed on the surface for up to 3 days and loosen with a splash of milk when reheating.
- Prep Time: 5 minutes
- Cook Time: 10 minutes
- Category: Sauce
- Method: Stovetop
- Cuisine: French
Keywords: White Sauce for Lasagna, béchamel sauce, white sauce, lasagna sauce, creamy sauce, French sauce
Frequently Asked Questions
Can I use white sauce instead of ricotta in lasagna?
Yes. Many white lasagnas skip ricotta and use only béchamel and mozzarella. The result is smoother and a bit lighter.
How much white sauce do I need for a 9×13 lasagna?
About 3 cups, which is this full recipe. Double it if you want a very creamy lasagna with extra sauce on every layer.
Can I use plant milk?
You can use unsweetened oat or soy milk and a plant-based butter. The sauce will be a little thinner, so simmer it a minute or two longer.
Can I make white sauce for lasagna ahead of time?
Yes. Press plastic wrap directly on the surface and refrigerate for up to 3 days. Warm it gently with a splash of milk and whisk until smooth before assembling the lasagna.