Firstly – nothing will keep forever if it is not stored correctly in the right environment. Many of these foods need to remain dry and be kept in their original unopened packaging or airtight containers.
All kinds of sugar, whether white, brown or powdered etc, will last forever if kept dry in an airtight container. Sugar will never spoil as bacteria simply cannot grow on sugar.
Dried beans were tested by Brigham Young University. They tested the long-term storage of pinto beans, and their conclusion was that pinto beans were safe to eat 32 years after they were stored in an airtight container at an ambient temperature.
White, wild, arborio and basmati rice all keep for 25+ when kept in their sealed packaging, or when stored in an airtight container. Brown rice does not store so well due to its high oil content.
Kept dry in its original box with the lid on, corn starch has an indefinite shelf life. Great for thickening soups and sauces post zombie apocalypse!
When stored unopened in its original packaging, powdered milk has an indefinite shelf life. Quick tip to determine if powdered milk has spoilt – if it has started to turn yellow, it’s time to bin it.
Due to its high sugar content and antibiotic properties, honey can remain edible for 1000s of years, even when opened! Edible honey has been found in Egyptian tombs.
All distilled spirits such as vodka, rum, whisky, gin and tequila, keep forever, even in opened bottles. Their color and taste may change over time, but they are still fine to drink.
Salt will never go bad if stored in a dry container and environment. It has the added benefit of being able to be used to preserve other fresh foods too.
Both apple cider vinegar and basic white vinegar will keep indefinitely when stored in a cool/dark cupboard. Vinegar also has countless cleaning, DIY and medical uses (see here)
Yeah those little bricks of noodles with the flavor packets, that cost 20 cents! They have been shown to last 10+ years, kept in their original packaging. Given the price or ramen noodles, stocking up on them is a no-brainer.