How long should fish food be kept?

Hello! I read on a web site that fish food should be thrown out after a certain period of time. I just have fish flakes so does anyone know how long I should be keeping these for? I heard if they are too old they taste like stale potato chips to the fish?

If you keep them sealed, dry and at a relatively constant temperature (inside the house, not the garage) the flakes should last a couple of years. At least that's been my experience with angel flakes from Angels+ and other flake food from Tetra Min.

PS: Fish need some variety, and a good way to provide it is with frozen, adult brine shrimp. Fish stores sell it in many package sizes, so start small. Just break off a small hunk, thaw it, and offer it to the fish. Fish may reject it the first few times but will soon like the stuff. Lots of other frozen foods are available, but brine shrimp has always worked best for me.