Why Doesn't Honey Spoil?

In a tomb in Georgia (the country, not the state), archeologists discovered a sealed case of honey. This honey hailed from 3500 B.C.E., millennia older than the previous oldest sample of honey ever found in Egypt. So of course, the researchers ate the honey.

What? It's fine! Honey may solidify or crystallize, but it can basically last forever! It's one of the few truly nonperishable foods.

But why doesn't honey spoil? To answer that, we need to explore how honey is made.

How Honey Is Made

We all know that bees make honey, but not everyone understands the process.

Worker bees go from flower to flower and collect nectar, a solution of sugars and proteins in water. The bees store the nectar in their honey stomach, a special organ containing enzymes that break down the sucrose in the nectar.

Then, the worker bees return to the hive and regurgitate the nectar to be ingested by house bees (worker bees that stay in the hive). Over about 20 minutes, the house bees continue to process the nectar in their honey stomachs until the nectar's sucrose is broken down into glucose and fructose.

Only then does the house bee regurgitate the nectar compounds into honeycombs. Then the substance is subjected to evaporation, which the bees accelerate by flapping their wings like fans. This causes the nectar solution to lose its water content and, over the course of 1-3 days, thicken into honey.

Why Honey Doesn't Spoil

First, honey doesn't have much water in it, with only 17% water content. This not only explains why honey is so sticky, but it also means that bacteria and other microbes can't thrive in it; there's just not enough water to sustain them. The water that remains in honey also lacks water activity (water that is actually viable for microbial growth in the first place).

Additionally, honey is acidic with a pH of 4, constituting a hostile environment for most bacteria.

So instead of growing in honey, bacteria and molds dehydrate and die, and thus can't contaminate the sticky-sweet treat.

Keeping Honey From Spoiling

Honey's non-perishable status does depend on taking proper care of it with responsible storage. Make sure to keep honey in a sealed container in a dry, cool place. Be sure to never introduce moisture to the honey; this means never dipping a spoon into it that has touched other substances like jam and keeping the lid tight and dry.

So long as the honey is not moldy, it's still good to eat. Even crystallized honey can be remedied by immersing the honey jar in hot but not boiling water for 15 minutes.

References: Why Doesn't Honey Expire? | Why Doesn't Honey Spoil? – The Chemistry of Honey | The World's Oldest Jar Of Honey Is From 3500 BC