Rata Honey
Rata
Honey is produced predominantly from the Southern
Rata on the West coast of New Zealand's South Island. While there are eight
Rata species (Metrosideros sp.) in New Zealand including some vines
as well as trees, Southern Rata (Metrosideros umbellata) is
the main honey source.
The Metrosideros genus has around 50 species throughout
the Pacific and South East Asia.
Another New Zealand Metrosideros species is Pohutukawa (M. excelsa)
known as New Zealand's Christmas tree, also a honey producer, it suffers from
flowering at a similar time to other competing nectar sources such as manuka
and rewarewa and few examples of Pohutukawa honey have the distinctive characteristics
of other Metrosideros species.
O-hi a lehua (M. polyganiflorum) endemic to Hawaii is another well known species and also an excellent honey producer with a similar honey to Rata.
Rata honey is very light in colour averaging
22 mm on the pfund scale
(Standard Deviation - SD 13.9mm) and distinctively flavoured with an almost
salty taste. The pollen is triangular and typical of the Myrtaceae (Myrtle)
family which includes eucalypts, bottle brushes (Callistemons), Australian
Ti Trees (Melaleucas) and leptospermums(manuka).
Another distinctive feature of the Myrtles is their similarity of flower structure.
A minimum of 45% Rata pollen is required to define a honey as Rata (Moar 1985)
but this must be accompanied by other characteristic data in the normal range
for Rata honey. Total pollen has an average of 160,000 pollen grains per 10
grams (SD 70,000)
Southern
Rata flowers from early January to March. The lowland trees start flowering
first and the flowering then progresses up to higher altitudes. In some areas
it is possible to see a distinct band of red cutting around the mountainsides,
the lower trees having finished flowering. The frequency of the Rata flowering
is sporadic, some saying it flowers well every 3 years and spectacularly every
7 years. This is an approximation only as it can flower well for 3 years in
a row and not at all some years making the honey supply intermittent. This
irregularity of supply is offset by Rata being one of the finest honeys in
the World, and when a good flowering coincides with with fine, stable weather,
it can produce a prolific crop of high quality with some producers exceeding
100 kilograms per hive.
"Fine weather" however is a commodity that is often lacking on the
South Island's West Coast. The "Coast" has a very high rainfall
with the Otira region averaging over 300 inches (7,620 mm) of rain per year
!
This contrasts with the Canterbury plains less then 100 km away which receives
only 25 inches (630 mm) per year. The main cause of this is the rugged Southern
Alps lying across the prevailing westerly wind producing wet and dry conditions
within only a few kilometres. While flowering intensity is a factor in the
Rata crop, the most important factor is a break in what is normally very wet
conditions.
Rata honey is one of our fastest
crystallizing honeys
with a proportionally high glucose content.
Average
Fructose 38.0% SD 2.2 Average Glucose 35.7% SD 2.6 (120 measurements ) This
can present problems to the producers extracting Rata honey. If they don't
get it extracted and processed ready for sale quickly, it sets hard and stays
in the combs! Because of this feature of Rata honey, it is impossible to present
it as a liquid honey without severe microfiltering and heat treatment. Rather
we utilize this characteristic to create one of our finest creamed honeys.
Another peculiarity of Rata honey is the almost complete absence of higher
molecular sugars. While the initial number of analyses showing this information
is low, these have shown an almost total absence of oligosaccharides. This
is a feature that could be used for floral source identification but generally
the other honey types associated with Rata honey are easy to separate. These
are typically Kamahi and Quintinea, both of which
flower earlier than Rata, have normally represented pollen spectra and are
darker in colour. Rata has also been shown to be low in some natural enzymes,
particularly diastase and invertase. This is something that is not unusual
in plants that evolved in parts of the World that were separated from European
flowering plants early in an evolutionary time scale.
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© 1999
Airborne Honey Ltd
