Yes, You Can Save And Store Leftover Béchamel Sauce

One of the classic French mother sauces, a velvety smooth béchamel sauce acts as the foundation for all sorts of dishes. If you've got some leftover from making a classic chicken pot pie or lasagna, you may be wondering if it's possible to store it to use at a later date. The good news is that you can — but you need to use it up rather quickly, and you have to store and reheat it the right way.

Homemade béchamel sauce will retain its quality for a day in the refrigerator, and could stay safe to eat for as long as three days. To keep your sauce in the best condition, transfer it to an airtight container. To prevent an unappetizing skin from forming on top, you could also lay a piece of plastic wrap or wax paper directly onto the surface before sealing the vessel.

Reheating leftover béchamel sauce requires a little care because of its delicate consistency, so you can't just sling it in the microwave and hope for the best. The easiest way to warm it up is in a pan, keeping the heat low, and stirring or whisking it to avoid lumps. If the sauce becomes too thick as it warms up, just add a splash of milk, and strain the mixture through a sieve if it gets lumpy. Alternatively, you could gently reheat the sauce in a double boiler or in a bowl set over a pan of simmering water.

If you want to keep béchamel sauce any longer than a day or two, you'll need to freeze it. The best way to do this is in smaller portions, which makes it easy to thaw and reheat as much sauce as you need. It makes the béchamel handy for small, individual dishes, such as a simple croque monsieur recipe or soufflés. Make sure the sauce is cool before you transfer it to the freezer in airtight containers or zip-top bags. Double bag the sauce if you're worried about it picking up odors from other frozen foods. It will keep for up to three months in the freezer. 

You'll need to thaw the frozen sauce before reheating it, and the easiest way is by letting it defrost in the refrigerator overnight. Or if you're in a hurry, you could keep the sauce in its container and run cool water over the top until it thaws.

When you're ready to use it, reheat the thawed béchamel in a saucepan, but be sure to keep whisking it as it heats up to break up any lumps. The sauce may also separate in the freezer, but don't worry too much, as stirring it well over gentle heat should help to bring it back to the right consistency. Alternatively, if you have the equipment, you could use a sous vide method to reheat sealed pouches of the sauce.