Science & TechFact
Properly stored honey keeps indefinitely.
Honey holds only about 18 percent water; the rest is sugar that pulls water out of any microbe. Add a pH of around 3.9 and hydrogen peroxide, which bees make from nectar with an enzyme. As long as the water content does not rise much above 18 percent, honey does not spoil. The tale of edible honey from pharaohs' tombs, however, is false.
Useful: Keep the jar dry and closed: moisture is the only thing that makes honey go off.
Source: en.wikipedia.org