I read about freezing pesto in ice cube trays (same with broth), which I'd love to do. But curious if you should cover or wrap the trays?
I do a quick set freeze then pop them out and put them in a freezer bag, I would cover them to protect them from absorbing odors if I was leaving them until use.
No, you don't have to. As soon as it freezes, pop them into a sealed bag. This works great for sauce reductions too.