Pick up any jar of New Zealand Mānuka honey and you'll usually see one of two ratings: UMF™ or MGO. Both tell you something about the honey's strength, but they are not the same thing. Here's a plain-English guide.
What is MGO?
MGO stands for methylglyoxal, a naturally occurring compound found in Mānuka honey and what makes it so distinctive. An MGO number shows how many milligrams of methylglyoxal are in each kilogram of honey. MGO 263+ means at least 263 mg/kg. The higher the number, the more concentrated the MGO.
MGO is a single measurement. It tells you about potency, but on its own it doesn't confirm that the honey is genuine Mānuka or that it's fresh.
What is UMF™?
UMF™ stands for Unique Mānuka Factor. It's a quality trademark run by the UMF Honey Association in New Zealand, and only licensed producers can use it. Hidden Honey holds UMF licence #3096.
A UMF rating is based on independent laboratory testing of four markers:
- MGO (methylglyoxal): the potency measure.
- Leptosperin: a compound found naturally in Mānuka nectar that can't be added artificially, so it helps confirm authenticity.
- DHA (dihydroxyacetone): converts into MGO over time, which helps show the honey will stay true to its rating.
- HMF: shows whether honey has been overheated or stored too long.
Because it checks authenticity, freshness and potency together, UMF™ is the more complete rating.
UMF to MGO conversion table
| UMF™ rating | Minimum MGO (mg/kg) |
|---|---|
| UMF 5+ | MGO 83+ |
| UMF 10+ | MGO 263+ |
| UMF 15+ | MGO 514+ |
| UMF 20+ | MGO 829+ |
| UMF 25+ | MGO 1200+ |
Which rating should you trust?
Both numbers are useful, but a UMF™ rating gives you more assurance because it covers authenticity and freshness as well as strength. When you see a UMF™ mark, you can look up the producer's licence number on the UMF Honey Association's list of certified brands.
If a jar only shows an MGO number, check that the brand is a New Zealand producer and that its honey meets New Zealand's government Mānuka honey definition for export.
What about Mānuka multiflora?
Multiflora Mānuka honey is a blend of Mānuka and other native flower nectars. It has a lower MGO level and a milder, smoother taste, which makes it a great-value everyday honey. Our Mānuka Multiflora is rated MGO 40+ and MGO 60+.
Find your grade
- Everyday spoonful: Discovery Range UMF 5+ or UMF 10+
- Richer and stronger: Discovery Range UMF 15+
- Our rarest small batch: Brothers Selection UMF 20+
Not sure which to choose? Read our guide: Which UMF grade should you buy?
Frequently asked questions
Is a higher UMF always better?
Not always. Higher grades are rarer and stronger in flavour. Many people enjoy UMF 5+ or 10+ every day and keep higher grades for special occasions or gifts.
Can MGO be added to honey?
Synthetic methylglyoxal exists, which is why UMF™ testing also checks leptosperin, a marker that can't be added artificially.
Where is Hidden Honey's Mānuka from?
Our hives are placed in remote Mānuka scrubland in Taranaki, on the west coast of New Zealand's North Island.