I have miso, bought three kinds two years ago. We don't use it much, czech kitchen is more about other tastes.

But can it spoil? I ferment and thought it's very salty, and it behaves like it. One year, jar long opened in a fridge, it's exactly the same I think.

The date on the glass is very innacurate, am I right? Or can it develop something nasty without me noticing?