Mature honey, put in a well-closed vessel and in a dry room, preserves its quality for unlimited time. For example, in Egypt, at the opening of the tomb of Pharaoh Tutankhamun, archaeologists have found pots of honey dating back approximately 3,000 years, which was still perfectly edible.
The secret behind honey’s eternal shelf life is a range of factors. Hydrogen peroxide, acidity and lack of water work together to make this sticky substance last forever. The ancient Egyptians used honey for a multitude of purposes including as a sweetener, a gift for the gods and an ingredient in embalming fluid.
When the pot is opened, the honey takes humidity from the air and begins to dilute the surface and ferment, which gives the honey an unpleasant smell.