How can I fix a grainy bechamel sauce?

[Joseph_L]

I just tried making a classic bechamel for my lasagna, but it came out a bit grainy instead of perfectly smooth. I'm wondering if I let the roux cook too long before adding the milk, or if my heat was too high when I incorporated it.

[NatalieL]

In my experience grainy sauce usually comes from adding milk too cold or too fast, which makes lumps you have to chase. If I keep the heat steady and pour the milk gradually while whisking, it tends to smooth out after a minute or two.

[SofiaA]

Could it be the roux wasn’t fully hydrated, or the flour didn’t disperse? I’ve had lumps show up when I dumped the milk in and didn’t whisk long enough afterward.

[Andrew81]

I once fixed it by straining or giving it a quick blast with an immersion blender for a few seconds, then kept stirring as it cooled.

[Scott_M]

Honestly I wonder if the real issue is something else in the lasagna process, like the sauce sitting on the noodles or the oven heat changing the texture later; sometimes it thickens oddly without a clear cause.