On Mon, Feb 28, 2022 at 10:19:15AM -0500, Prof. Levine wrote: > The only problem that I can see is if you open a package, use only part of > it, and put the rest in a plastic bag that is not sealed and put it in the > refrigerator. Or Shabbos leftovers. This is actually not just a corner case. Tir'u baTov! -Micha