UMF Explained: What the Number on Your Manuka Honey Jar Actually Means

You’ve seen Manuka honey in specialty stores, on wellness shelves, in the premium section of a grocery store. And you’ve probably noticed the number on the label — UMF 10+, UMF 15+, UMF 20+.

What does UMF actually mean? And does the number matter?

The short answer: yes, it matters quite a lot. Here’s what you need to know.

UMF™ is a trademarked certification system used to grade and verify genuine New Zealand Manuka honey. It’s managed by the UMF Honey Association, an independent body based in New Zealand.

The key word is independent. The UMF™ grade on a jar is not assigned by the producer. It’s earned through testing by an accredited laboratory and issued by an independent certification body. The producer cannot simply print a UMF™ number on the label — they have to submit each batch for testing and pass before the mark is applied.

This matters because the Manuka honey market has a history of mislabelling. Independent certification is what separates a verified grade from a number someone chose for marketing purposes.

Here’s where it gets interesting — and where UMF™ is meaningfully different from other grading systems.

The UMF™ test measures three specific compounds that occur naturally in genuine Manuka honey:

Leptosperin. A compound found only in Mānuka nectar. Its presence confirms that the honey genuinely came from the Mānuka plant (Leptospermum scoparium), native to New Zealand. No other plant produces leptosperin. It cannot be added. If it’s in the honey, the honey came from Mānuka flowers.

DHA (Dihydroxyacetone). A naturally occurring compound in Mānuka nectar that converts to MGO as the honey matures. High DHA means the honey was made from genuine Mānuka nectar, and that the MGO concentration is likely to develop further over time.

MGO (Methylglyoxal). The compound most people have heard of. MGO is measured to indicate the concentration level of Manuka-specific activity. The UMF™ number on your jar corresponds to the verified MGO concentration alongside the other markers.

Testing all three together is what makes UMF™ a stronger verification than systems that only test MGO. You can increase MGO artificially. You cannot fake leptosperin.

The higher the UMF™ number, the higher the certified concentration of Manuka markers in that batch. Here’s a straightforward breakdown:

• UMF™ 5+ – Mild, smooth flavour for everyday enjoyment
• UMF™ 10+ – Balanced intensity with richer Manuka character
• UMF™ 15+ – Bold, robust flavour for those who enjoy a stronger profile
• UMF™ 20+ – Premium grade with deeper flavour and limited availability
• UMF™ 24+ and higher – Rare, highly concentrated Manuka honey produced in small quantities

Choosing a grade is a matter of taste, frequency of use, and personal preference — not simply choosing the highest number.

You’ll see both UMF™ and MGO on Manuka honey jars in the US. They’re not the same thing.

MGO refers to a single compound — methylglyoxal. Some brands measure only MGO and display that number on the label. MGO measurement is useful, but it’s one data point.

UMF™ is a multi-marker certification system. It measures leptosperin, DHA, and MGO together, and requires independent third-party verification before the mark can be applied.

A jar can display a high MGO number without having passed the full UMF™ certification process. If authenticity and independent verification matter to you, UMF™ is the mark to look for.

For a full side-by-side comparison and conversion tool, see our UMF™ & MGO Converter.

Yes — and that’s normal, not a problem.

Manuka honey is a natural product. The concentration of Manuka markers in a batch depends on factors like climate, flowering conditions, and harvest location — things that vary from season to season. A batch of honey from the same hive location might grade differently in a warm season compared to a wet one.

This variability is part of what makes genuine Manuka honey a natural product rather than a standardised commodity. The UMF™ grade on each jar reflects what was in that specific batch, tested at that specific time.

When you’re buying Manuka honey in the US, here’s what to check:

1. The UMF™ logo — the trademarked mark, not just the letters “UMF”
2. A UMF™ grade number — displayed alongside the logo
3. A batch or lot number — indicates traceability
4. New Zealand origin — genuine Manuka honey comes from New Zealand

At Happy Valley, all our Manuka honey is UMF™ certified. Every batch is tested by an accredited laboratory before the grade is applied. The jar in your hand traces back to a specific season, region, and batch — from our family’s hives in New Zealand.

If you’re new to Manuka honey, UMF 10+ is the most common starting point. The flavour is noticeably different from regular honey, the grade is widely available, and it gives you a clear sense of what genuine Manuka tastes and feels like.

For help choosing between grades and formats, use our Choosing the Right Manuka Honey guide.

• UMF™ & MGO Converter
• UMF™ Certification & Lab Testing
• Shop Manuka Honey