Why honey never spoils

Honey found in Egyptian tombs has been tasted by archaeologists and pronounced perfectly edible. It is not a preservation miracle. It is chemistry doing something quietly brutal to any microbe that tries to live there.

Honey is roughly 80% sugar and under 18% water, and the sugar is hygroscopic: it pulls water out of anything nearby, including bacterial cells. Add a pH around 3.9 and traces of hydrogen peroxide produced by an enzyme bees add during processing, and you have an environment almost nothing survives.

The caveat is moisture. Leave honey open in a humid kitchen and it will absorb enough water to allow fermentation. Sealed, it simply waits.