If you’ve ever looked at a jar of Mānuka honey, you’ve probably noticed numbers like UMF 10+ or UMF 15+ on the label. You may also see another number called MGO.
But what do these ratings actually mean?
Understanding the UMF™ system can help you choose authentic, high quality Mānuka honey and understand the unique properties that make this honey so special.
What Is the UMF™ Rating?
UMF stands for Unique Mānuka Factor. It’s an independent quality trademark used to identify genuine Mānuka honey produced in New Zealand.
The UMF rating measures key natural compounds that make Mānuka honey unique. The higher the UMF™ number, the higher the concentration of these compounds in the honey.
Unlike simple honey grading systems, UMF is based on multiple scientific markers, helping ensure the honey is authentic, pure, and produced to strict standards.
The Four Factors Tested in UMF Honey
To receive a UMF rating, Mānuka honey must pass laboratory testing that measures four key markers:
MGO (Methylglyoxal)
This is the compound most responsible for Mānuka honey’s unique antibacterial activity. Higher MGO levels indicate stronger potency.
Leptosperin
A naturally occurring compound found only in Mānuka nectar. Because it cannot be artificially added, it helps verify the honey’s authenticity.
DHA (Dihydroxyacetone)
This compound occurs naturally in the nectar of the Mānuka flower and gradually converts into MGO as the honey matures.
HMF (Hydroxymethylfurfural)
A freshness indicator that helps ensure the honey has not been overheated or stored for too long.
Together, these four markers help guarantee that the honey is genuine New Zealand Mānuka honey and meets strict quality standards.
What Does the UMF Number Mean?
UMF ratings range from 5+ to 25+ (or higher). The number reflects the strength and concentration of the honey’s natural compounds.
As a general guide:
UMF 5+ – 10+
A great everyday honey that can be enjoyed as a natural sweetener or as part of a healthy lifestyle.
UMF 10+ – 15+
A popular choice for daily wellness and general use.
UMF 15+ – 20+
Higher potency honey with stronger levels of beneficial compounds.
UMF 20+ and above
Premium, high-strength Mānuka honey with very high concentrations of active compounds.
What Is MGO in Mānuka Honey?
Alongside UMF, many jars of Mānuka honey also display an MGO rating.
MGO stands for methylglyoxal, a naturally occurring compound found in Mānuka honey that contributes to its unique antibacterial properties.
The MGO number simply indicates the amount of methylglyoxal present, measured in milligrams per kilogram of honey.
For example:
MGO 263 means there are 263 mg of methylglyoxal per kg of honey.
Higher MGO numbers indicate higher potency.
How UMF and MGO Compare
While both ratings are useful, they measure slightly different things.
MGO measures just one compound, methylglyoxal.
UMF, on the other hand, measures four different markers to confirm potency, authenticity, and freshness.
That’s why the UMF system is widely considered the gold standard for grading authentic Mānuka honey.
However, the two numbers are often displayed together to help consumers better understand the honey they’re buying.
As a general guide:
UMF Rating Approximate MGO Level
UMF 5+ MGO 83
UMF 10+ MGO 263
UMF 15+ MGO 512
UMF 20+ MGO 826
These values are approximate, as natural honey can vary slightly between batches.
Choosing the Right Mānuka Honey
The best UMF rating for you depends on how you plan to enjoy your honey.
Many people choose:
- UMF 5+ or 10+ for everyday use in food and drinks
- UMF 15+ or higher for more concentrated Mānuka honey
No matter the grade, choosing UMF certified honey helps ensure you are getting authentic Mānuka honey that has been independently tested.
Why Watson & Son Displays Both UMF and MGO
Watson & Son includes both UMF and MGO ratings on their jars so customers can clearly understand the strength and quality of their honey.
This transparency helps customers see exactly what they’re getting, from the honey’s certified authenticity to its natural potency.
Combined with careful harvesting and the brand’s PureFlow™ process, this helps ensure every jar delivers the quality and consistency Watson & Son is known for.
