Which food never spoils?

Honey, for the reasons that make it honey: too little water for a microbe to live in, acidic, and carrying a trace of hydrogen peroxide from the bees' own enzymes. Sealed pots recovered from Egyptian tombs have been found still edible after three thousand years.

It is not quite alone. Salt and sugar keep indefinitely for the same reason honey does - nothing can grow in them. Dried rice, pure spirits and properly stored ghee last decades to centuries. What honey has is the distinction of being a complex, sweet, ready-to-eat food that needs no processing to survive.

The one important exception is infants. Honey can carry dormant spores of Clostridium botulinum, which are harmless to anyone with a developed gut but can germinate in a baby's, and it should not be given to children under one year old. The food that outlasts civilisations is the one thing you keep away from the youngest person in the house.