Asklemmy

Do you mean a true expiration date, as in "this food is not safe to eat", or just best by?

If it's the first, I tend to trust my nose and eyes up to a point, depending on the type of food stuff that can grow things that will make my anus prolapse get treated more by the exact date than my nose, same with stuff that's hospital bills in food form. If the date is up, that kind of stuff goes out even if I can't detect anything off, because the risk/reward just isn't favorable. Similarly, if my nose does pick up something off, idgaf what the date is, it gets trashed.

It does help that I've got creeping on 40 years of kitchen exposure and a damn sensitive nose.

But best by? Most of the time, a properly sealed container of something that was safe when it was put in the container can take weeks or months past the best by date, when unopened, to have a noticeable change in taste. Some stuff, particularly canned and freeze dried goods, you can sometimes open them years later and have no detectable difference from something freshly packaged. Obviously, it isn't everything, since some stuff preserves better than others, but food safety isn't usually affected at all.

You gotta be more careful with meats, as an example. It won't necessarily spoil, but it goes tasteless and textureless before some other ingredients.

It really is a case by case basis though. Something like canned tomato soup? It'll taste exactly the same for years. Something like minestrone, though, you go to to a year after best by and you'll notice everything being extra mushy, and the flavor gets blander. Sometimes, even a few months past in that specific soup.

But freeze dried? I've never had anything freeze dried be worse over time if the package is still sealed. That's kinda the point of freeze drying. If it does change, it's on a scale of decades, assuming a good seal on the packaging.

Things like salt pork, there's a fairly firm time limit on. Less so with pickled vegetables, though texture gets bad with some things. Regular dried meats, like jerky, unless it's vacuum sealed, it'll get kinda blah within a week or two of the best by date. Dried fruits, peppers that kind of thing can last years even without packaging. I had a big box of dried peppers that lasted like five years and the last chili I made with them was just as good as the first. Not a bit of difference in taste, texture, or heat level.

Worst thing I ever had that was past best by was deviled ham. I'm not even a fan of the stuff to begin with, but you wanna talk about something getting funky and even more sludgy, holy crap. It even smelled like vomit. Well more than usual lol.