Pass the shiraz: variety the spice of life for Australian wine growers

The world’s wine markets have become far more competitive over the past decade, but despite the competition, Australia’s mix of winegrape varieties is not very different from the rest of the world’s. Since 2000, it has become even less differentiated.

Wine producers are always on the lookout for new ways to differentiate their product to attract and retain consumer (and supermarket) attention, but Australia to date has made little headway in diversifying its vineyards.

Even though there are very large differences in growing conditions across Australia, cross-regional varietal differences within Australia are much less than is the case within other countries. This suggests there is plenty of scope to explore alternative varieties in the various regions of Australia – something grapegrowers are doing in any case as they consider ways to adapt to climate changes.

These are some of the insights gleaned from a new resource that reveals what winegrape varieties are grown where in the world, and offers winemakers data that could be used to make critical decisions.

Climate adaptation by Australia vignerons, for example, could involve switching to more resilient southern European grape varieties, and/or sourcing grapes from higher latitude or altitude regions if wineries’ wish to retain their current mix of grape varieties. And growing novel varieties could generate a point of difference in a winery’s offering. Responding in these ways requires information on trends in varietal plantings here and abroad.

The 2010 database compiled by researchers at the University of Adelaide includes 520 regions in 44 countries, thereby covering 99% of global wine production; and it includes over 1,270 winegrape varieties.

Measuring uniqueness

The researchers developed a Varietal Similarity Index, or VSI, to measure how close one region’s varietal mix is to another’s. This indicator has a complex formula, but it simply ranges between zero and one. A VSI value of zero means a region’s varietal mix has no overlap at all with that of another region (or the rest of the world, or its own region in a different year), while a VSI value of one means the two regions have exactly the same shares of bearing area under particular grape varieties.

In 2000 the VSI between Australia and the world was 0.45, which was 9th highest in the world. But it rose to 0.62 by 2010, making it 3rd highest in the world after France and (marginally) the United States. Meanwhile, the average of the VSIs for all other countries in the sample hardly changed, at 0.35. In other words, Australia was much less distinct than the average country in its varietal mix in 2000, and its distinctiveness became even less so by 2010.


Winemakers are looking to alternative grape varieties in response to changing climates. RobW_/Flickr

How different are wine regions within Australia?

Notwithstanding the very large differences in growing conditions across the country, varietal differences between regions within Australia are more muted than is the case within other countries. The average of its regional VSIs of 0.53 is not much below Australia’s national VSI of 0.62 in 2010, and is almost double the average regional VSI of other countries in the sample. In France for example, where each region is required by law to grow only a small number of varieties that have been designated as most suitable for that region, the average of its regional VSIs is 0.29.

True, some regions in Australia have managed to pull away from the pack and so are more differentiated from the national mix now than in 2000. However, a little over one-fifth of Australia’s 74 regions in the database, comprising 40% of the national winegrape area in 2010, changed their varietal mix hardly at all (the VSI of their mix in 2010 vis-à-vis 2000 was 0.97 or higher). For another one-fifth of Australia’s regions, accounting for 22% of the national area, their VSI was 0.95 or 0.96. It was only the small remainder of regions, comprising only about one-third of Australia’s winegrape area, that had a VSI between their varietal mix in 2000 and 2010 that was less than 0.95.

How important are emerging varieties becoming in Australia?


Emerging winegrape varieties in Australia – 2001 to 2012. Blank spaces mean data are unavailable, rather than zero. Anderson and Aryal (2013a), ABS (2012) and Phylloxera Board of SA (2013). 

There are only 10 varieties whose areas in Australia have grown significantly from less than 200 bearing hectares since 2000 (left-had side of table above), if one ignores varieties in the world’s top 20 list. Furthermore, in aggregate those ten raised their share of Australia’s total area by only 1.7%.

Increase in bearing area by variety, Australia, 2001 to 2012. Derived from Anderson and Aryal (2013a) and ABS (2012).


The eight varieties whose area in Australia expanded most over the first decade of this century (see chart above) are, apart from Viognier, all in the top 20 globally. The share for Shiraz alone rose 6 percentage points over that decade, while Chardonnay’s rose 5 points and the shares of Sauvignon Blanc and Pinot Gris each rose 2 points. And two-thirds of what has been removed in Australia since 2000 is Sultana, whose area globally fell by three-quarters over the 2000-10 period – adding to the country’s drift towards the global norm. The right-hand side of the table above refers to those very minor varieties whose plantings have taken off in the past few years. But these make up only a small fraction of 1% of the national area.

What role for Shiraz?

World’s top 35 wine varieties in 2010, compared with 1990 and 2000. Anderson (2013, Chart 12).


Australia popularised Shiraz/Syrah in the 1990s, which led to many other countries expanding their plantings of this variety. In 1990 it was 35th in the area ranking of all winegrape varieties globally. But by 2000 its area had trebled, and by 2010 that had nearly doubled again, bringing Shiraz to the 6th position on that global ladder and just below the areas of the two now-most-widespread varieties, namely Cabernet Sauvignon and Merlot (see chart above).

Australia contributed to that expanding area of Shiraz, but expansion was even greater in France and Spain. There were also large plantings in other key New World wine countries, and in Italy and Portugal. As a result, Australia is no longer as globally dominant in this variety: its share of the global Shiraz area has dropped from 29% in 2000 to 23% in 2010 – even though Shiraz has increased its share of Australia’s own vineyards over that decade, from 22% to 28%. Partly because of these changes for Shiraz, the mix of varieties in Australian vineyards is becoming more like the global average.

What next?

Evidently, Australia’s mix of winegrape varieties is not very different from the rest of the world’s, leaving plenty of scope to explore alternatives.

Australia may have made little headway in diversifying its vineyards to date, but there is much discussion of alternative or emerging varieties in the media and at conferences. Consumers will hope this leads to greater diversity in future as wine growers continue to strive to understand their terroir and raise the quality of their offering.

Kym Anderson receives funding from Grape and Wine Research and Development Corporation.

The Conversation

This article was originally published at The Conversation. Read the original article.



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