The short answer is that shredded cheese can last for several weeks to several months after it's been opened, depending on the type of cheese and how it's stored. For example, cheddar and monterey jack tend to have a longer shelf life than soft cheeses like brie or goat cheese. It's kind of like how apples last longer than bananas, you know?
But here's the thing: the quality of the cheese can start to deteriorate over time, even if it's still technically safe to eat. It's like when you leave a loaf of bread out for too long and it starts to get all stale and gross. You can still eat it, but it's not going to taste as good as it did when it was fresh.
