Old Mutual Trophy Wine Show 2012: Brian Croser on vineyard management
By Christian Eedes, 29 May 2012
“The spectre of leaf-roll virus hangs over everything,” says Brian Croser, innovator in the Australian wine industry for 35 years and international judge at the Old Mutual Trophy Wine Show in 2004, 2009 and again this year. “The impact is part real and part psychological – I suspect it gets blamed for too much”.
During this year’s competition, Croser judged Bordeaux-style red blends, other red blends, Pinot Noir and Shiraz and so is well positioned to assess the strengths and weaknesses of South African red.
Across just about all categories, he detects too many wines displaying a “stewed veggie” character – caused by unduly highly levels of pyrazine while the tannins in evidence are also problematic, these often being “aggressive, angular and astringent” and not “fine-grained and sandy”.
Instead of seeing virus at the fundamental cause of all shortcomings, Croser says he thinks inappropriate irrigation and canopy management in the vineyard is also playing a big part. Optimal fruit ripeness gets compromised because growers get nervous pre-veraison (the onset of ripening) and supply too much water and then not enough once ripening is under way.
“A dry soil is the crucial signal to the vine to start produce the ripening hormone abscisic acid. Ideally, what you want is the sudden and complete onset of the riprening process and this is achieved by turning the roots over to moderate stress by withholding water. Once ripening is under way, you want to maintain root and canopy condition and that’s the time to turn the water on,” he says.
As for high pyrazine levels in local reds, Croser speculates that this is due to grapes which didn’t get sufficient sun exposure early enough in the ripening process. “Early leaf stripping can make a huge difference,” he says.
As for the matter of sunburn and potential over-ripe or dead fruit, he advises to retain the canopy higher up, shoots leaning over and providing an umbrella effect. In any case, Croser believes South African winemakers are “schizophrenic” about full-ripeness. “It’s what you should naturally produce but you seem to want to avoid it all costs”.
Shiraz is a particular disappointment in this respect, Croser saying that the wines in general appeared “modest in terms of colour and dimension”. One of the possible reasons for this is that most producers are pre-occupied with making Shiraz “in the Rhône mould” despite the fact that this will only be possible in a few, very special locations. “Your natural niche is at the riper end of the flavour spectrum”.
South Africa should not despair of achieving refinement, however. The high quality wine producing areas of Australia and Chile are generally cooler than those of South Africa observes Croser but he is convinced that those sites do exist locally where the twin goals of ripeness at low alcohol and refined tannins can be achieved. “You have a matrix of topography and soils that nobody else has”.