While condiments seem as though they’ve all got an indefinite shelf life, ketchup actually can go bad. Because of the acidity of the tomatoes and vinegar, and the amount of sugar, ketchup has a pretty long shelf life. An unopened container of ketchup can remain stored for up to two years past the printed expiration date.
Once the bottle is opened, it will last for another year in the refrigerator. If you’d rather keep your ketchup at room temperature, the shelf life for an opened bottle in your pantry is about a month, though you should check for signs of spoilage before consuming the ketchup.