Cereal, when open, will go stale from air exposure after three months. This can vary if it contains nuts, which are prone to rancidity.
Nuts and seeds are high-oil items and thus can go rancid after a couple of months.
Avoid keeping dried herbs to keep their flavor and quality intact.
Baking powder and baking soda lose their leavening power over time.
Typical peanut butter can be kept in the kitchen pantry, but if yours is the organic one, it is better suited in the fridge.
Ketchup and mayonnaise can easily go bad in just weeks when left unrefrigerated.
The shelf life of quinoa is longer when they are kept in well-isolated containers.
Contrary to the common belief, canned veggies will start to break down and get a metallic taste when kept in the pantry for a long period of time.
Brown sugar when kept open tends to dry up and harden after four months.
Garlic when kept in a dark and cool spot in the pantry for more than three to five months, may shrivel or begin to sprout