Honey is a unique food in that it never spoils. Properly saturated honey should stay safe to eat forever.
In fact, one study found “stored honey from Ancient Egypt to be over 3000 years old and still completely edible”. http://www.compoundchem.com/2014/08/21/chemistryofhoney/
So Why Doesn’t Honey Spoil?
Honey safely stores for long periods of time for many of the same reasons why canned goods store for so long without refrigeration. Each capped cell in the honeycomb is very similar to a Mason jar in your pantry filled with food stores.
Honey is made from nectar that bees collect from flowers. They bring the nectar back to the hive and it is stored in the wax cells of the comb. The bees fan the nectar with their wings evaporating the water from the honey. When the honey is saturated enough, the bees cap it for safe storage.
Finished honey has about a 17% water content, which is interesting because when we boil maple syrup, we reduce it to a 17% concentration before we can it. Maple syrup also stores safely for long periods of time.
Honey is a high concentration of Fructose and Glucose. So high, that it is almost a solid. This is why honey often crystallizes…but more about that later. The saturation is so high that there isn’t enough water in the honey to support the growth of bacteria and mold spores. The bacteria actually suffocate or dehydrate.
Similarly, if you’ve ever canned jellies or jams, you know that a LOT of sugar is usually required in the recipe. This isn’t just to make the jam extra sweet, all that sugar is functional in keeping the jam safe while stored. Bacteria doesn’t thrive in super saturated amounts of sugar.
The second reason that honey is resistant to spoilage is that it is an acidic food. Bacteria doesn’t like acidic conditions. We can use the canning example again here. If you’ve ever canned tomatoes, you might be aware that a simple 10-15 minute water bath is perfectly acceptable in preserving tomatoes in jars. As opposed to green beans for example, a less acidic vegetable that requires a pressure canner to can safely. Tomatoes are high in acidity. Because of this, they don’t require the high temperatures and long exposure in boiling water to make them safe.
Honey can be stored in jars without any heating or canning process. The natural antibacterial properties keep it safe.
Often stored honey will become crystallized. The color will lighten and it will become opaque and textured similar to sticky wet sand.
If this happens to your honey it does not mean that it is spoiled. In fact, quite the opposite. Like I mentioned before, honey is so concentrated that it is almost a solid. The sugar is just a few water drops away from being a sugar crystal. If water does evaporate, the glucose will crystallize. This crystallization begins a chain reaction and will spread rapidly though the jar. The honey is still perfectly safe to eat in its crystallized form.
The concentration of crystallized honey ensures that the bees were able to evaporate the nectar to 17% before you harvested. Sometimes honey frames will contain uncapped honey cells. If you harvest this along with the capped cells, you are mixing more water into the finished honey. This opens up the possibility of spoilage.
What to do with Crystallized Honey
Usually I just leave it be. I find that it spreads easier on toast. The heat from the toast melts the crystals and turns the honey clear again.
But if you want your honey back to its golden, clear hue, boil a pan of water, turn off the heat and let the jar soak until the honey is clear again.
The jar on the right was heated and the crystals went away leaving smooth golden honey.
Honey can contain small amounts of botulism which is harmless to adults and older children, but younger children especially under the age of 1 should not consume honey.