In 25 years, Manuka honey has grown from anonymity to world-wide notoriety—and because it has raised awareness of the healthful properties of honey—it has become a darling of the honey health industry. Its rise in popularity is the result of scientifically authenticated anti-bacterial properties. Yet for those who like a richly flavored honey, this honey is equally at home on the table. The fact that this is a native plant combined with the “clean and green” policies in New Zealand also make it possible to obtain plausibly organic versions of this honey.
Manuka honey is a distinctively flavored honey with thixotropic properties. This means that it is gel-like in liquid form, and becomes less solid when stirred or shaken. It is slow to granulate and forms coarse crystals, for this reason it is often creamed. Its color is dark cream to tan or dark brown. It is aromatic with damp earth and heather notes and a cool menthol (or eucalyptus) taste and rich flavor of mineral, barley sugar and herbs. It is medium sweet with a slightly bitter aftertaste. In its creamed form, the honey has a cool, smooth feel in the mouth. It is particularly good as comb honey.
Manuka honey is primarily obtained in New Zealand from the Manuka or Tea Tree, Leptospermum scoparium and also from the Kunzea ericoides (Kānuka, White tea-tree or Burgan and classified as Leptospermum ericoides prior to 1983). Although these two plants are distinguishable by the smoothness of their foliage, the honey produced by each is virtually indistinguishable by pollen, taste and aroma. The honey from both is called Manuka honey. These species likely originated in Australia/ Tasmania, where there are dozens of Leptospermum species known collectively as Tea Tree or Jellybush. The name Tea Tree arose from the custom of making tea from the leaves, purportedly coined by Captain Cook. In Australia, this honey is known as Tea Tree honey or Jellybush honey or even Leptospermum honey, and share many of the same characteristics as New Zealand’s Manuka honey (recently a honey with the same properties as Manuka has been found to be produced from Leptospermum polygalifolium, from Australia).
Although there is an oil derived from Manuka, the popular Tea Tree Oil is not produced from the Leptospermum species of plants. Tea tree oil is produced from the Australian group of trees of the Melaleuca genus, named similarly as another source of tea. It is from Melaleuca plants that the well known tea tree oil is produced.
Despite the current popularity of its honey, Manuka was considered an invasive weed in New Zealand and was targeted for eradication in the 1950’s. Manuka honey was considered low quality and beekeepers tried to avoid collecting it because its jelly-like consistency made it hard to extract from the hive. It is now recognized not only as ecologically important, but also as a natural resource of economical, ornamental and medicinal value. In New Zealand, north islanders knew of the healing properties of Manuka honey. It was used on wounds and to settle upset stomachs and intestinal complaints. But it wasn’t until Dr. Peter Molan, MBE, of Waikato University’s Honey Research Unit, proved the special antibacterial properties of Manuka that the stage was set for official world-wide recognition.
All honey is antibacterial to some degree and has been used to treat wounds for thousands of years. This is mainly the result of a chemical process within honey that produces hydrogen peroxide, a well known antibacterial and cleansing agent. The key difference with Manuka is antibacterial properties not related to hydrogen peroxide (known as NPA or Non Peroxide Activity). What Molan discovered was an additional, unidentified anti-microbial factor that he called UMF® or Unique Manuka Factor. He found that the strength of the property was not consistent across different types of honeys nor in fact, from different sources of the same type of honey (this was later determined to be due to both the dilution of manuka honey by other honey types and the variety of L. scoparium harvested). He then developed a test to determine the degree of UMF® strength or activity. This was measured and given a UMF® activity value. Typical activity values are 10+ to 40+. The higher the activity, the higher price it commands. In a brilliant marketing move, Manuka honey producers in New Zealand decided to protect the value of their unique honey from unsubstantiated claims of other honey producers and formed the Active Manuka Honey Association – AMHA (renamed Unique Manuka Factor® Honey Association – UMFHA in July 2011) with sole use of the UMF® title. Only honey producers that are members of the AMHA may use the UMF®; title and the AMHA actively protects their trademark. Honey testing facilities at the University of Waikato Honey Research Unit are open to anyone, but results will be given as levels of hydrogen peroxide and non-hydrogen peroxide activity and no UMF® value.
The unidentified factor? It has been discovered to be MGO, or methylglyoxal, a compound found in all honey and other foods such as wine, coffee and chocolate, but in much lower levels. And indeed, some honeys are now rated by the amount of MGO contained. However, this is not considered a true measure of the antibacterial activity of the honey. Apparently there is an unidentified synergistic component in honey that affects the efficacy of MGO.
As more has been learned about the source of the antibacterial properties of honey, new measurements have been created to rate these properties in honey. Questions about the reliability of the UMF® rating, and research showing that MGO levels do not relate directly to increased antibacterial activity, have led to new methods of measuring the activity of honey. Dr. Peter Molan himself has released his own testing method called The Molan Gold Standard which is backed by the University of Waikato. This rating is available to any honey producer.
Determining actual bio-activity levels of honey is challenging. Producers are using a wide variety of measures to rate their honey. Along with UMF® and the Molan Gold Standard, here are a few more.
-AAH (Antibacterial, Antioxidant Honey)
-MGO, which measures the amount of MGO
-Active and activity
-Bio-active and bio-activity
-NPA (Non Peroxide Activity)
-any prominent number between 1 and 50, with or without the symbol +.
To help reduce confusion and maintain confidence in their honey products worldwide, the government of New Zealand is supporting the creation of an enforceable standard for bio-activity in honey through The Bee Products Standards Council
Just how important is the activity rating? Undoubtedly quite important when applied topically for skin conditions, wounds and internally for fighting harmful gut bacteria, but the importance of these ratings is minimal when buying honey for eating. There are many healthful reasons for eating most kinds of honey and the most important consideration in my opinion, is minimal processing and additive-free to retain the beneficial properties of the honey.
AKA: Red Tea Tree, Māori: ‘mānuka’,
Latin Name: Leptospermum scoparium and Leptospermum polygalifolium (recently discovered to have similar properties as L. scoparium)
Honey Origins: New Zealand and Australia
Peter Molan’s Research and Papers
AMHA – UMFHA Official Website
The Molan Gold Standard
Mānuka/kāhikatoa & kānuka
Effect of Manuka Honey on Enterobacteria
Ongoing research papers concerning antibacterial properties of honey