Manuka Honey produced in New Zealand is typically sent to one of two independent labs to be tested for dietary Methylglyoxal (MG or MGO). The value of the honey when sold from producer to packer is directly proportional to this test result. Manuka honey should either be labeled with the actual MG test results (in mg/kg), or with a correlated rating on the UMF (Unique Manuka Factor) scale. The UMF trademark must be on the jar if they are using a UMF rating instead of the actual MG test result. Honey labeled with the UMF logo and rating is also tested for two additional chemical markers (HMF & Leptosperin). The relationship between MG & UMF is as follows (after threshold HMF and Leptosperin levels are met):
When you see anything else on a label of honey purporting to be Manuka honey, you should steer well clear. Examples of what continues to show up on labels include: “Active”, “Bio-Active”, “Total Activity ”, “K-Factor ” plus a number typically ranging from 5+ to 20+. When labeled this way, the company is trying to intentionally mislead the consumer into thinking they are getting a high MG (or legitimate UMF) honey when in reality they are typically getting a very low concentration, or low activity (i.e. low MG value) honey.
Most consumers are shocked to learn that 80% of the purported Manuka honey in the US market employ these misleading labeling tactics. Shop with confidence: https://www.beesandtrees.com/collections/manuka-honey
For a more in-depth look at the laboratory testing of Manuka honey, you can read this article by Steve Howse, Analytica Laboratories, published in The “New Zealand Beekeeper.” DHA and MGO: The Most Common Testing in Manuka Honey.