Masters of the Climate: Innovative farmers ... - South West NRM

eading every 20 minutes over three
months.
Erl was working on a hunch: that unusually
hot days in the month before harvesting
could affect the flavour of the grapes, and
therefore the quality of the wine that could
be made from them.
‘It’s quite dramatic here when you get heat
spikes,’ he said. ‘The maximum daily
temperature is normally about 25ºC.Then
it suddenly jumps up to 38ºC and you can
see there’s tissue damage occurring.
Scientific work supports this – if the
temperature departs too much from the
norm too quickly and humidity is low and
wind is up, plants stop photosynthesising
and they don’t recover.
‘For a couple of weeks in February the land
tends to influence our temperatures much
more than the sea.That’s when the damage
is done.’
THE CRITICAL TEMPERATURE
FOR GRAPE FLAVOUR
Erl needed one vital piece of information
for his analysis. What was the cutoff point
of maximum temperature, after which
grape flavour was affected?
‘I looked at temperatures in the classic
wine growing regions in France, such as
Burgundy. I found that these regions had no
more than 500 degree hours of
temperatures over 22ºC during the month
of ripening. That gave me a benchmark
figure – if you get more than 500 degree
hours over that level, don’t expect to make
classic wines!
‘All chemical reactions are driven by time
and temperature. The berry is a little
chemical factory. It synthesizes flavours.The
berry will happily make its flavours at 22ºC
and it will hold on to them much better if
the temperature rarely rises above that
figure.’
With this information, Erl concentrated his
study area on the coastline between
Dunsborough and Albany in the south west
corner of Western Australia. With the
combination of the data from the
temperature loggers and an Excel
spreadsheet, he quickly found out where
the heat load was favourable. One hundred
kilometers south of Dunsborough looked
perfect. The Happs purchased additional
land at Karridale and focused their grape
growing activities on the second property.
‘Viticulturally speaking it’s a paradise
because no matter what variety you grow,
the south coast conditions give you a very
long season,’ said Erl.‘The grapes mature in
ideal conditions. You won’t get the heat
spikes that destroy the flavours.’
FURTHER RESEARCH INTO
PLANT PERFORMANCE
Unlike the other Masters of the Climate
participants, the Happs did not have to deal
with a major drought in the last five years.
‘This part of the world has ideal
temperatures for growing any grape
variety,’ said Erl. ‘Our winter rainfall is like
clockwork, and although our soils are old
and leached, they’re ideal for grapevines
which can conserve mineral elements from
year to year.’
While other farmers across Australia
struggled to survive, Erl was able to
continue his study into temperature and
find other applications for the data. He now
aims to:
estimate the potential of a site to reliably
ripen a cultivar;
identify the range of cultivars that will
succeed on a certain site, so that the
grower can blend different varieties or
widen their product range;
quantify the risk of frost, winter freeze,
rainfall, disease or any other site-related
circumstance that might jeopardise the
enterprise;
work out whether physiological ripeness
might coincide with sugar maturity; and
ensure that ripening conditions will be
favourable to the conservation of flavour
in the berry.
‘I am collecting data across each 24 hour
period and accounting for the experience
that a plant has in the zones that are critical
to its performance. It gives me a much
FROM THE 1999 CASE STUDY…
According to Happ, the change in climate in Europe from
Dijon to Marseilles (450 km) is about the same as that
between Frankland and the South Coast of WA, some
140 km.Therefore a careful measure of the environment
is more critical in Australia than in France…
Happ’s conclusion is that appropriate land management
for quality wine production begins with selecting sites,
choosing varieties and predicting ripening times for each
combination of site and variety.
The next step is to check the temperature for one month
prior to ripening to look for hot spells which might reduce
the content of flavour producing substances.Then the
grower can choose the best combination of site and
variety to produce quality fruit.
The only objective way to determine if Happ’s innovations
have succeeded in improving wine quality is to taste new
wines, yet to be released. He maintains that the
differences are obvious, even to the untrained palate.
FROM THE 2004 CASE STUDY…
‘I published three papers in the Australian and New
Zealand Wine Industry Journal,but nobody took any notice.
Then last year I heard from viticulturalists in Virginia on the
east coast of the United States.They were very interested
in my theories on temperature and invited me to come and
make a presentation.
‘I worked through what I’ve done about grape flavours and
heat spikes, and then I went on to my current research into
trying to predict when a grape variety will ripen. In the
United States many people are gathering temperature data
and they mostly use it for predicting pest activity or the risk
of disease like powdery mildew. But once the data’s there,
it can be used for other purposes.They were fascinated.
‘My objective is to take data from any part of the world and
look back at the ripening conditions and know what you
can expect before you even plant a grape. It’s much more
complicated than I first imagined and I’m still working on it.’
Erl has now enrolled at Curtin University to develop his
ideas further in a Masters of Science by research.
Websites
www.happs.com.au - the site for the Happs
winery, which also contains Erl’s research papers on
temperature and grape flavour.
better idea of why it behaves as it does
under different thermal regimes,’ said Erl.
‘In summary, I’ve got a much more accurate
account of the thermal environment than
you can get by simply looking at the daily
maximum and minimum temperature.’
If you come across Erl and Ros Happ’s
premium wine, the Three Hills 1999 Shiraz,
I suggest you drink to that.
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