According to Insider, a good rule for ketchup is that once opened, it should last around six months if you keep it in the fridge. ... Eat by Date says that if you are regularly using your ketchup and notice it has begun to separate and has a watery layer on the surface, it is still safe to eat but might soon be spoiled.

How do I know if my ketchup is spoiled?

How can you tell if opened ketchup is bad or spoiled? The best way is to smell and look at the ketchup: if the ketchup develops an off odor, flavor or appearance, or if mold appears, it should be discarded.

Can ketchup go bad and make you sick?

After all, you never know what might happen to you if you don't. For example, while food poisoning incidences from eating expired ketchup are rare, they're still possible.