Jars of honey three thousand years old have turned up in Egyptian tombs, still edible. That is no legend, and it comes down to two things: honey holds less than 18 % water, and it is acidic. No bacterium, no yeast settles in those conditions.
So why the date on the jar? Because regulation demands one on any packaged food. That date speaks of quality, not safety. A honey two years past it is eaten without risk.
What actually spoils honey
Heat, light and moisture. In that order.
Above twenty-five degrees, honey gradually loses its enzymes and its hydroxymethylfurfural level climbs. That compound is what laboratories measure to tell whether a honey has been heated or stored too long in the warm. A jar left near the stove ages ten times faster than one in a cupboard.
Moisture comes in on the spoon. A wet spoon, or one that has been in the yoghurt, brings water and micro-organisms with it. That is the only real way to ferment honey at home.
The signs that mislead, and the ones that do not
Honey that hardens, pales, turns grainy: all is well. Crystallisation is a normal physical process and hits glucose-rich honeys first. Our article on keeping honey liquid covers the subject in detail.
A whitish film on the surface, what beekeepers call honey bloom, causes no problem either. It is trapped air rising.
A sour or alcoholic smell, bubbles climbing, a lasting foam and a taste that stings: there, the honey has fermented. That happens to honey too moist at the start or contaminated by a spoon. Throw it out.
Should you cook with honey
Better not to heat it. Above forty degrees the enzymes break down; above sixty, little remains to separate honey from sugar syrup.
In baking the point is not to give up but to choose. Use a simple, inexpensive honey for a cake that goes in the oven, Orange Honey (90 dh) for instance, and keep your characterful honeys raw: on toast, in yoghurt, at the very end of cooking.
To loosen a crystallised honey, use a warm water bath at forty degrees maximum, or simply leave the jar a few hours near a gentle heat source. Never the microwave, which heats in spots and burns locally.
Where to keep it
A cupboard, away from light, between fifteen and twenty degrees, lid firmly closed. Not the fridge, which speeds up crystallisation and brings nothing in return.
Honeycomb Honey (100 dh) is the exception: keep it cool and eat it within the year, because the wax eventually dries out.