Most genuine high-grade manuka honey from New Zealand includes a UMF rating on the label. Some honey producers instead use an MG or MGO rating. Honeys without a UMF or MG/MGO rating are generally low-grade honey without the beneficial characteristics that have made premium manuka honey so much in demand.
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NPA stands for non-peroxide activity, the property that makes certain grades of UMF and MGO manuka honey special. Those manuka honeys that carry only a ‘total activity’ or ‘peroxide activity’ rating do not have this special NPA property and should be considered low-grade honey.
UMF ratings are based on specific natural markers characteristic of manuka honey, such as leptosperin and methylglyoxal. UMF ratings correspond to the potency of the desirable NPA properties of honey. Typically honey with NPA between 5 and 9.9 are labelled UMF 5+, honey with NPA ratings between 10.0 and 14.9 are rated UMF 10+, and so on.
MGO is methylglyoxal, sometimes referred to as MG.
Use this table to convert between manuka honey UMF, MGO and NPA ratings.
|UMF Rating||Minimum MGO*|
** NPA is measured as % solution (%w/v) of phenol/water
Examples of how to read this table:
UMF 15+ honey has a minimum MGO 514.
MGO 400 honey would be rated UMF 12+ (or UMF 10+).
MGO 550 honey would be rated UMF 15+.
UMF 20+ honey has a minimum MGO 829.
This graph from a scientific research paper shows the correlation between MGO and NPA. Graph courtesy Andrew Robinson, The Honey Store.
The official UMF honey association website umf.org.nz at one stage offered an online calculator that converted from MG/MGO to NPA/UMF and back the other way.
That UMF Association MGO/UMF calculator is no longer available.
Instead, use our free online UMF vs MGO calculator.