Ancient honey is still edible after thousands of years

Honey is the only food that never spoils. You could walk into an Egyptian tomb from 3,000 years ago, crack open a sealed clay jar, and spread the contents on toast without getting sick.

Its immortality comes from a "perfect storm" of chemistry. Honey is naturally very acidic, with a pH that kills almost anything that tries to grow in it. It is also extremely low in moisture; it is so dry that it sucks the water out of bacteria through osmosis, effectively dehydrating them to death.

When bees make honey, they vomit it up. During this process, an enzyme in their stomachs called glucose oxidase mixes with the nectar. This enzyme breaks down into hydrogen peroxide—the same stuff you use to disinfect cuts in your kitchen cabinet.

Honey is essentially a concentrated sugar-acid-peroxide bomb that is inhospitable to life. As long as the lid stays on and moisture from the air can’t get in, the chemical seal remains permanent.

Interestingly, because of these properties, honey was used for centuries as a wound dressing to prevent infection long before we understood what bacteria were.