The visibly never ending shelf-life of honey is surprising: archaeologists have excavated honey from thousands of years ago, and it’s still unspoiled. One reason is that as a substance, honey has very low moisture, an environment in which very few bacterias can survive. Another is that it is very acidic, again a characteristic that bacterias don’t like. Finally, the bees produce hydrogen peroxide from the nectar, a known antiseptic, to the point that honey can be used in traditional medicine to treat wounds against infection. In a word, honey is hell for bacterias and other microorganisms, so as long as it is sealed and not mixed with anything, they won't dare grow on it and spoil it.