She threw out salt because it was past the "best by" date. Mind you, that salt has spent millions, possibly billions, of years in the ground. I asked why. She said, if the manufacturer says that, why would they lie?
I don't often find myself reaching out for facepalm memes or "SMDH", but I sure did then. I just said okay, but don't ever throw out salt again.
A best by date implies it is stored properly even then there’s a difference in taste/quality before and after the best by date. Which is not true for salt.
https://www.fsis.usda.gov/food-safety/safe-food-handling-and...
So there you go. Also, if you look at context, the poster I replied to asserted that salt clumping was not a change in quality (hence the form of my reply).
Salt can spoil due to humidity if not properly stored within a day, or may never spoil, ever, if stored properly. That kind of spoilage has nothing do to with age and hence my issue with a best by date for salt.