Does Honey Go Off? Shelf Life, Storage and Signs

Honey does not go off the way most foods do. A sealed jar kept dry and at room temperature stays edible for years, because honey is an unwelcoming place for the organisms that spoil food: it holds very little available water, it is a supersaturated sugar solution, and it is acidic. What honey does do is change — aroma fades, colour darkens, a laboratory marker called HMF climbs — and under two conditions it can genuinely fail. This guide covers the mechanism, the law behind the date on the jar, and the signs that tell a set jar from a spoiled one.

Honey keeps because it holds too little available water for spoilage organisms to grow. It is not unchanging, and honey that takes up moisture can ferment.

Plate I · ArtefactRecord

Why doesn’t honey go off?

Three features of its composition, working together.

Very little water. The Honey (England) Regulations 2015 cap the moisture content of most honey sold in the UK at 20%, and 23% for heather honey. The FAO’s beekeeping manual puts the practical line lower: “Only honeys with less than 18% water can be stored with little to no risk of fermentation.”

Very little available water. Total and available water are not the same thing: most of honey’s water is held by the dissolved sugars around it, and what matters to a micro-organism is water activity. Chen’s 2019 survey in Foods reports that “the Aw for honey ranges from 0.50.65”, that the limiting water activity for yeast in honey is “about 0.610.62”, and that a threshold below 0.60 prevents osmotolerant yeast growth. Spoilage bacteria and moulds need far more.

Sugar and acid. The FAO describes honey as “an oversaturated sugar solution, i.e. it contains more sugar than can remain in solution” — the supersaturation that also makes it crystallise. Organic acids, gluconic acid chief among them, make it acidic: the FAO tabulates an average pH of 3.91 across US honeys, range 3.42 to 6.10.

That describes what can live in the jar. How the water gets that low is covered in how bees make honey.

Fig. I · The water-activity ruleDiagram

Total and available water are not the same thing, and what matters to a micro-organism is water activity. The scale below runs the length of honey’s own stated range.

Water activity (Aw)Honey’s stated range

Below 0.60 — osmotolerant yeast growth preventedAbove 0.60

0.500.65

0.60Threshold

0.61–0.62Yeast’s limit

Honey — Aw 0.5 to 0.65

Chen’s 2019 survey in Foods reports that “the Aw for honey ranges from 0.5~0.65”.

Threshold — 0.60

A threshold below 0.60 prevents osmotolerant yeast growth.

Yeast’s limit — about 0.61–0.62

The limiting water activity for yeast in honey.

Not placed on this scale

Spoilage bacteria and moulds need far more. This page gives no figure for them, so none is drawn.

Honey’s stated range runs to 0.65, and the yeast limit sits at about 0.61 to 0.62 — inside that range, not beyond it.

Does honey go out of date? What “best before” means

Honey carries a date, and that date is about quality rather than safety. Government guidance states that a best before date “tells you when the food might start to reduce in quality”, and that “after the best before date, the food is usually safe to eat but may not be of the same quality”. The other form is the safety one — “use-by dates on food labels tell you when the food is no longer safe to eat” — and it belongs to perishable foods such as meat and ready-to-eat salads. Honey is marked with a best before.

Why does something this stable carry a date at all? Because the law requires one. Retained Regulation (EU) No 1169/2011 requires a date of minimum durability on prepacked food, and Annex X exempts only a short list — vinegar, cooking salt, solid sugar, sugar confectionery, chewing gum, wine, drinks of 10% alcohol or more, unpeeled uncut fruit and vegetables, and bakery eaten within 24 hours. Sugar is on that list. Honey is not, so it must be dated.

Annex X fixes the wording too — “Best before …” where the date names a day, “Best before end …” otherwise, and the year alone will do for foods keeping longer than 18 months. The length of the date, though, is the packer’s own judgement: the law governs its form, not its span.

How long does honey last, and what changes with age?

Longer than most cupboard staples, but not unchanged. Three things move — slowly at room temperature, fast with heat.

• HMF rises. Hydroxymethylfurfural is, in the FAO’s words, “virtually absent in newly produced honey” and forms “during storage or during heating”, which makes it “the main indicator of honey deterioration”. UK law allows at most 40 mg/kg for most honey, 80 mg/kg for declared tropical origin.
• Diastase activity falls. The enzyme activity used as a freshness marker declines with heat and time. UK law sets a minimum of 8 on the Schade scale, and a floor of 3 for naturally low-enzyme honeys whose HMF is no more than 15 mg/kg.
• Colour darkens and aroma fades. Visquert, Vargas and Escriche stored raw honeys at 25, 30, 35 and 40 °C and recorded “decreases in luminosity, whiteness index, hue and chroma with the increase in temperature and storage time” — the jar goes darker. Their own caveat belongs with it: honey type had “a much greater influence on HMF … and colour than storage conditions”, and the storage treatments “did not alter the characteristic colour of each type of honey as long as the commercial requirements for freshness parameters were met”. The FAO adds the sensory half: above 25 °C, most honeys “lose much of their aroma in just a few months”.

Heat is the clock in all three. HMF and diastase are also how a raw claim is checked batch by batch — see what raw honey is and testing.

Can honey go bad? The two ways it does

Fermentation. This is the one genuine spoilage of honey, and it needs water. Osmotolerant yeasts grow once enough of the water in the jar is available to them, and the FAO’s threshold — little to no risk below 18% water — sits below the legal ceiling of 20%. Lawfully sold honey can therefore occupy the band between roughly 18% and 20% where the risk is real. Crystallisation can tip it: partly crystallised honey “may present preservation problems”, says the FAO, because water freed as glucose crystallises out concentrates in the liquid phase.

Fermented honey announces itself: sour, yeasty or alcoholic on the nose, foaming at the surface, sharp or fizzy to taste, sometimes pressing against the lid as gas builds.

Moisture picked up from the room. Honey is hygroscopic. The FAO is precise: “normal honey with a water content of 18.3% or less will absorb moisture from the air at a relative humidity of above 60%.” A jar left open in a steamy kitchen, or dipped with a wet spoon, gains water at the surface — which is exactly where fermentation begins.

Fig. II · Two ways in, one place they meetDiagram

Two paths in — both arrive at the same place

Lid left off — damp air

Honey is hygroscopic. The FAO is precise: “normal honey with a water content of 18.3% or less will absorb moisture from the air at a relative humidity of above 60%.”

SealedThe lid keeps humid air off the surface.

A wet spoon

“A jar left open in a steamy kitchen, or dipped with a wet spoon, gains water at the surface.”

Dry spoonA clean dry spoon each time — a wet spoon puts water back in.

The surface layer

Where both paths end, and “exactly where fermentation begins”. It announces itself: sour, yeasty or alcoholic on the nose, foaming at the surface, sharp or fizzy to taste, sometimes pressing against the lid as gas builds.

The body below

Drawn unchanged, and no path reaches it. This page puts the water gain, and the start, at the surface — the body is drawn as a place the arrows do not go, not as a promise about the rest of the jar.

Osmotolerant yeasts grow once enough of the water in the jar is available to them.

Has my crystallised honey gone off?

No. Crystallisation is glucose coming out of solution as solid crystals — a physical change, reversible with gentle warming, and no change to what the honey contains. A set jar that smells and tastes like honey is honey. Why some set in weeks and others stay liquid for years, and how to soften one (often searched as “decrystallize”), is in our guide to crystallised honey. Grain alone is never spoilage; sourness, foam and fizz are.

How should honey be stored?

• Sealed, with a clean dry spoon each time: the lid keeps humid air off the surface, and a wet spoon puts water back in.
• At room temperature, in a cupboard. Cool and steady beats warm and variable: heat drives HMF up and aroma out.
• Dry and dark. Away from the kettle, the hob and the window.
• Not in the fridge. Crystallisation runs fastest at around 14 °C, and the FAO records virtually none above 25 °C or below 5 °C. A fridge sits at the cold edge of that range, and a jar passes through the fast band on its way in and out. Chilling buys nothing: honey needs no refrigeration, and a cold jar is stiff to spoon.

Does the honey found in Egyptian tombs prove honey never expires?

It is the story everyone reaches for, and it does not carry the weight put on it. What Howard Carter recorded in Tutankhamun’s tomb were two pottery vessels, 614j and 614k, inscribed in hieratic “honey of good quality”. Alfred Lucas, the excavation’s chemist, reported that they “were practically empty, except for a trace of dried material adhering to the inside”, and that when he analysed the trace from one of them the chemical tests were negative — though Lucas added that this does “not necessarily mean that the specimen had not been honey at one time”, only that if it was, it had changed beyond the reach of the usual tests. The livelier version — a jar of still-liquid honey from the tomb of Yuaa and Thuiu — fares worse: Lucas found “little doubt that the sample is Castor Oil that has become very acid”.

Surveying the field in 1975, F. Filce Leek found that although it “seems to be accepted as a fact that many samples of honey have been recovered from ancient Egyptian tombs”, authentication by pollen analysis was essentially absent — and pollen analysis of three museum samples he obtained, carried out at the British Museum (Natural History), authenticated none of them as honey or honeycomb. His own verdict was that judgment “should be reserved on samples thought to be ancient honey or honeycomb until a pollen investigation has been made”.

So the modest version is the sound one, and the chemistry above explains it: sealed, dry and cool, honey keeps for a very long time. “Honey never expires” rests on finds the records do not support. What the ancient record does document is honey’s standing — jars labelled for quality, sealed for a king — covered at honey in the ancient world.

Who should not eat honey?

Honey of any kind is not suitable for infants under 12 months. NHS advice is not to give a child honey until they are over one year old, because honey can occasionally contain bacteria that produce toxins in a baby’s intestines, causing infant botulism, a very serious illness. Age, storage and processing do not change that. Bee products, honey included, are also allergens for some people — a fact about the category, stated as one.

Where THYMELIA stands

THYMELIA is a UK house of Greek foods working two harvests — raw thyme honey from Chania in western Crete, and early-harvest olive oil from the hills above Kalamata, where the wild thyme flowers from May to July. Shelf life is a composition question, which makes it a testing question: moisture, HMF and diastase decide how a jar ages, and they are the figures we intend to publish per batch. There is no shop yet, and we name no date for one. Our range will not be uniform — some products will carry a raw claim and some will not, and the word will appear only where the batch figures stand behind it. How we source is at sourcing, what we will test at testing, and what the published research on honey actually reports at evidence. The same question about the other harvest — where the answer is the opposite, because oil does degrade — is at does olive oil go off?.

Storage is one corner of a larger subject; the category from the top is gathered at raw honey.