describe how to store the bechamel source?

Answer 1

Place it in a lidded, non reactive container (plastic or glass) press a piece of plastic wrap onto the top of the sauce to that air can't get to the sauce and then cover with the lid of the container. Store in the refigerator no more than three days.

Answer 2

Store in an air tight container in the refrigerator. Don't leave the sauce outside of the refrigerator for more than 10 min with not using. It will crystallize and get hard, then it is pretty much garbage. Your sauce should last for a couple days with proper care.