Does Honey expire?

Honey is roughly 80% sugar and only about 17% water, so its water activity is far too low for bacteria or yeast to grow; it is also mildly acidic, and the glucose oxidase bees add to it produces small amounts of hydrogen peroxide. Sealed honey therefore keeps essentially indefinitely, which is why jars found in ancient tombs have been reported as still edible. What people mistake for spoilage is crystallisation — glucose coming out of solution as fine crystals — which happens to almost all raw honey and is reversed by standing the jar in warm water. The one genuine rule is that honey must never be given to a child under twelve months, because it can carry Clostridium botulinum spores that an infant gut cannot handle.

How to store it

• Room temperature with the lid on; refrigeration speeds crystallisation.
• Use a dry spoon — water introduced into the jar is the one way to start fermentation.

How to tell it has gone

• Crystals and cloudiness are normal. A fizzy, alcoholic smell means water got in and it has fermented.

"Use by" and "best before" are legally different. Use-by is a safety date and should be respected; best-before is about quality, and food is usually fine well past it. Where the two diverge matters, the page above says which applies.