Manuka Honey UMF and MGO Explained: How the Grading Actually Works

Manuka honey is honey made predominantly from the nectar of Leptospermum scoparium, a scrubby flowering shrub native to New Zealand and southeastern Australia, known in New Zealand by its Maori name, manuka. Bees work it the same way they work clover or orange blossom: they gather nectar, add enzymes, fan out the water, and cap the finished cells. The mechanics are identical to every other honey on earth, and we walk through them in how bees make honey. What is different is the nectar's chemistry, and that difference is the entire commercial story (Wikipedia: Manuka honey).

Because the plant grows in a narrow part of the world and blooms for a short window, genuine manuka is a supply-limited product. That scarcity, combined with a strong global reputation, is why a small jar can cost more than a gallon of domestic wildflower honey, and why the category attracts both careful certification bodies and opportunists. Everything below exists because the market needed a way to tell one from the other.

MGO on a label is short for methylglyoxal, an organic compound that occurs at trace levels in many foods and at unusually high levels in manuka honey. The number after it is a concentration: milligrams of methylglyoxal per kilogram of honey. MGO 263+ means the tested batch carried at least 263 mg/kg. That is the whole definition. It is a measurement, not a grade curve, not a rating, and not an opinion (Wikipedia: methylglyoxal).

The interesting part is that the bees do not make it. Manuka nectar contains an unusual amount of dihydroxyacetone, or DHA, a simple sugar-derived compound. After the honey is made and stored, DHA slowly converts into methylglyoxal. So the MGO number in a jar is the product of two things: how much DHA the nectar carried, and how long and how warm the honey has sat since. A fresh batch may test low on MGO and high on DHA, then climb over months in the warehouse. This is why any serious grading system looks at both numbers rather than the headline one.

Treat DHA as the fuel tank and MGO as the fuel already burned. A honey with high DHA and modest MGO is young and still converting; a honey with low DHA and high MGO has largely finished the reaction. Both can be genuine manuka, and neither is a defect. What matters to a buyer is that the number on the jar was measured on that batch, by an accredited lab, and printed rather than estimated, which is exactly the discipline a certification scheme enforces and a marketing word does not.

It also explains a common shopper complaint: two jars of the same brand and the same stated grade can taste and pour differently. Manuka is a natural product with an in-jar chemical clock running. Batch variation is normal. A dramatic mismatch between the label and what is in the jar is not, and the batch or lot number printed on a certified jar is your route back to the lab report.

UMF stands for Unique Manuka Factor. It is a trademarked quality mark administered by the UMF Honey Association, and it is licensed to brands rather than printed at will. To carry the mark, a packer must be a licensee, must have batches tested by approved laboratories, and must pass on four markers rather than the single potency figure (UMF Honey Association):

Marker	What it tells you
Leptosperin	Authenticity. A compound found in manuka nectar that cannot practically be added or faked, so it separates real manuka from blended or spiked product.
DHA	Potential. The precursor still in the jar, which indicates the honey's freshness and how the MGO figure may develop.
MGO	Potency. The measured methylglyoxal concentration, the number most brands print on the front.
HMF	Freshness and handling. Hydroxymethylfurfural rises when honey is heated or stored badly, so a low figure indicates the honey was not cooked to look clear.

That is the practical difference between UMF and a bare MGO figure. A standalone MGO number tells you one thing about the jar. A UMF grade tells you the same thing plus that an association-approved lab checked the honey is genuinely manuka and was not heat-abused on the way to you. Both are real information; UMF is simply more of it, under a licence that can be revoked.

This is the table people come to this page for. The UMF Honey Association publishes the equivalence, so any certified jar's UMF grade maps directly onto a minimum MGO value. Print it, screenshot it, take it shopping.

UMF grade	Equivalent MGO (mg/kg)	Where it sits in the market
UMF 5+	MGO 83+	Entry certified. Mild, table honey, cheapest genuine tier.
UMF 10+	MGO 263+	The common starting grade. Most people's first certified jar.
UMF 15+	MGO 514+	The popular mid-to-high tier. Strong flavor, gift-worthy.
UMF 20+	MGO 829+	Premium tier. Scarce, intense, priced accordingly.

Grades above 20+ exist and follow the same logic, climbing steeply in both MGO and price. Two practical notes. First, a jar labeled only with an MGO figure that falls between rungs, MGO 400+ for instance, is not a UMF grade; the honest brands that do this state their UMF grade separately, as Manuka Health UMF 13+ / MGO 400+ ($34.95) does on its own label. Second, MGO figures are minimums, so a jar tested at 300 may still be sold as MGO 263+ under its certified grade.

Separate from UMF, the New Zealand government sets a legal definition of what may be exported as manuka honey, and it splits the category into monofloral and multifloral tiers based on a chemical and DNA test panel rather than on marketing. This is why exported jars carry that classification language, and it is another reason to prefer product whose paperwork exists (Wikipedia: Manuka honey).

For a shopper the takeaway is short: monofloral manuka is the product the reputation was built on, multifloral manuka is real manuka blended with other nectars from the same landscape, and both are legitimate as long as the jar says which it is. A jar that says neither, from a brand with no licence and no lot number, is asking you to take its word for it.

Of the four UMF markers, leptosperin deserves its own moment. It is a naturally occurring compound in manuka nectar that survives into the honey and that, crucially, is not commercially available to be spiked in. Methylglyoxal, by contrast, can be manufactured. That asymmetry is the whole anti-fraud argument for a multi-marker test: a bad actor can in principle push an MGO number up, but a leptosperin test asks a question that only real manuka nectar can answer.

You will rarely see leptosperin printed on a front label, and that is fine. It runs in the background of the certification. What you should look for on the jar is the licensee number that says a body with something to lose ran those tests, which is precisely what a certified jar such as the New Zealand Honey Co UMF 15+ (MGO 514+) ($33.88) carries.

Now the decoder ring for everything that is not UMF or MGO. These terms are not necessarily dishonest, and some sit on genuinely good honey. They simply are not standardized, which means you cannot compare one brand's number to another's, and you cannot convert them to MGO.

Term on the jar	What it is	Comparable to UMF or MGO?
UMF 15+	Licensed grade, four markers, approved lab.	Yes. This is the reference standard.
MGO 514+	Measured methylglyoxal in mg/kg.	Yes, for potency. Says nothing about authenticity or heat.
KFactor 16 / KFactor 22	A single company's proprietary scale, weighted toward pollen count and origin rather than MGO.	No. It does not convert to an MGO figure.
Active 12+ / Bio Active 15+	Legacy or in-house wording. Historically referred to a general activity test, not a manuka-specific one.	No. Treat as unverified unless an MGO or UMF figure appears beside it.
TA (Total Activity)	An older non-manuka-specific measure.	No.
"Raw manuka", "premium", "wild"	Descriptive words with no grading content.	No.

The rule of thumb we use at the desk: if the number on the front cannot be found on the UMF conversion table or expressed in mg/kg, it is a brand's own scale. Buy it if you like the brand, but do not pay a UMF 15+ price for it.

Six checks, in the order we do them, and the whole thing takes about fifteen seconds in an aisle or on a product page.

#	Look for	Why
1	A UMF grade or an explicit MGO mg/kg figure	If neither is present, there is no measured potency claim at all.
2	UMF licensee number	Confirms the mark is licensed rather than decorative.
3	Country of origin and packing	Manuka is a New Zealand and Australian product. Packed elsewhere is a question worth asking.
4	Batch or lot number	The thread back to a specific lab report.
5	Net weight in grams or ounces	Jar sizes vary enormously in this category. Price is meaningless without it.
6	Monofloral or multifloral wording	Tells you whether it is pure manuka or a landscape blend.

A jar that clears all six, at any grade, is a fair purchase. A jar that clears none of them is a jar of unidentified honey with a famous word on the front. Both a New Zealand Honey Co UMF 10+ (MGO 263+) ($18.88) and its higher grades put the UMF mark, the MGO equivalence, and third-party testing language on the label, which is the pattern to look for.

Manuka pricing does not scale linearly, and higher grades are occasionally the better value per unit of the thing you are paying for. The calculation is simple: divide the price by the MGO number to get dollars per MGO point, then multiply by 100 so the numbers are readable. Here is the math on the listed prices we verified, ordered from most to least expensive per point.

Jar	Grade	Listed price	Cost per 100 MGO points
Manuka Health UMF 13+ / MGO 400+ (250g / 8.8oz listed)	MGO 400+	$34.95	about $8.74
New Zealand Honey Co UMF 10+	MGO 263+	$18.88	about $7.18
New Zealand Honey Co UMF 15+	MGO 514+	$33.88	about $6.59
New Zealand Honey Co UMF 20+	MGO 829+	$32.98	about $3.98
Egmont Honey MGO 265+ / UMF 10+ (500g listed)	MGO 265+	$26.99	about $10.18

Read that table with one large caveat printed in bold, because the honest version of this math needs a third variable: net weight. The Egmont jar looks worst per MGO point and is a 500g jar, roughly double the size of a standard 250g manuka jar, so per gram of honey it may be the cheapest row on the table. The Egmont Honey Manuka MGO 265+ / UMF 10+ 500g ($26.99) is the jar to reach for if you actually eat manuka rather than dose it by the spoon. The complete formula is price divided by grams divided by MGO. Do that once, on the two jars you are torn between, and the decision makes itself.

The other lesson in the table is that the trophy grade is not automatically a rip-off. At the prices we verified, New Zealand Honey Co UMF 20+ (MGO 829+) ($32.98) was the cheapest per MGO point of the small-jar options, which happens when a retailer discounts a high tier. Prices move constantly in this category, so run the math on the day rather than trusting a rule about grades.

Our honest routing, with no medical framing attached to any of it. If you are curious and want to taste what the fuss is about, buy a certified UMF 10+ and nothing fancier; it is genuine, it is the cheapest real entry, and it tastes unmistakably like manuka. If you use it regularly in the kitchen, buy the biggest certified jar of a modest grade you can find, because you are buying honey, not points. If you are buying a gift, UMF 15+ is the grade that reads as a serious present without entering collector pricing, which is why it dominates gift sets, and we cover the wider gifting field in honey gift sets.

Where high grades genuinely earn their price is flavor intensity and, for the people who buy them, the confidence that comes with a tested number. Manuka at UMF 20+ is thick, dark, mineral, almost medicinal in taste, and a little goes far. Whether that is worth the multiple is a personal call, and our ranked picks across the whole category live in the best manuka honey guide.

Manuka behaves differently from a runny clover honey in the jar, and shoppers regularly mistake normal behavior for a defect. Genuine manuka is typically thick and often thixotropic, meaning it is gel-like at rest and loosens when stirred or spooned hard. It also tends to be creamy and opaque rather than glass-clear. None of that is a fault, and none of it is a grading signal.

Store it like any honey: sealed, at room temperature, out of direct sun, and away from steam. Do not refrigerate it, which accelerates crystallization. If it does set firm, warm it gently in a water bath rather than a microwave; excessive heat drives up HMF, which is one of the four things the UMF panel measures, so cooking your expensive honey degrades exactly the metric you paid for. The full storage and rescue routine, including the temperature ceiling, is in does honey go bad.

The category's open secret is a supply arithmetic problem: for years, the volume of honey sold worldwide as manuka has been widely reported to exceed the volume New Zealand actually produces. That gap is the reason certification exists at all, and the reason a multi-marker test that includes leptosperin is worth more than a single printed number.

None of this makes the category a scam. It makes it a category where paperwork is the product. The practical defense is the six-point label check above, buying licensed UMF where possible, and treating an unusually cheap high-grade jar as the anomaly it is. The same instinct applies one aisle over, where the global honey supply has its own adulteration problem, covered in raw honey vs regular honey.

Here is our guardrail, stated plainly: we are not going to tell you that manuka honey does anything to your body, because that is a question for a clinician and a regulator, not a shopping guide. What we can describe is how people use it. Traditionally, manuka is eaten straight off a spoon, stirred into warm (not boiling) drinks, spread on toast, or taken as a soothing sweetener in a hot lemon drink, a household habit with a long history in New Zealand and in the countries that import it. People also buy it as a gift and as a pantry luxury. If you have a health question about manuka honey, ask your doctor or pharmacist.

Two hard safety facts that apply to manuka exactly as they apply to every other honey. Honey is not safe for infants under 12 months of age, because it can carry dormant bacterial spores that a baby's gut is not yet equipped to handle; this is a firm and universal caution from food safety authorities (FDA). And people with bee-product or pollen allergies can react to honey and to related hive products such as pollen and propolis, so if that is you, treat a new jar with the same caution you would any new food.

The honest comparison: manuka is a specific varietal honey with an unusual nectar chemistry, a certification system, and a scarcity premium. Domestic raw honey from a good producer is a fresher, cheaper, more versatile everyday food that will do everything manuka does in a cup of tea for a fifth of the price. They are not competitors so much as different purchases, in the way that a bottle of everyday olive oil and a finishing oil are different purchases.

If your interest is really in flavor rather than certification, the varietal world is much bigger and much cheaper than the manuka aisle, and we mapped it in the honey varieties guide. If your interest is in unprocessed, traceable domestic honey, that field is ranked in best raw honey. And if you are going to cook with any of it, read cooking and baking with honey first, because heat is the one thing that reliably degrades an expensive jar.