Sealing a cereal box keeps it fresh for a year, whereas opening it makes it stale after three months. This may vary if it contains rotten nuts.
With so much oil, nuts and seeds go rancid after a few months. Put them in a transparent freezer bag and refrigerate for a year to stay fresh.
People keep dried herbs indefinitely, but they shouldn't. The concern is quality, not food safety, as rancidity would reduce flavor and intensity.
Over time, baking powder and soda lose their leavening strength, making a sad cake! So use fresh ingredients before baking.
Organic peanut butter will get rotten in the pantry, although regular peanut butter can be stored. Organic peanut butter, like other nut butters, should be refrigerated.
Ketchup and mayo can spoil in weeks if kept unrefrigerated. If opened, refrigerated ketchup should be eaten within a month. Mayo takes 10–12 weeks.
The fat content of healthy grains like quinoa determines their shelf life. Because of heat, air, and moisture, their beneficial oils degrade and pass their peak. Use well-isolated containers.