Will climate change tweak the taste of Australian wine?

Climate sceptics aside, it seems to be well accepted across the wine industry that average global temperatures are likely to rise in coming years and that there will be an unavoidable consequence for the wine industry. Regions that were once warm will need to deal with even hotter conditions, and those that have been historically cool climate by definition might need to adjust their winemaking practices in order to deal with the impact of higher temperatures through the growing season.

And for Australian producers, climate change could have a significant effect. Our biggest selling varietal is shiraz; and mainly the “big” juicy type that are palate pleasing to the retail consumer. Around the world, Australian shiraz has become synonymous with ripe, jammy styles that fill the mouth and excite the senses. But as the rising heat ripens fruit earlier and more quickly, might it reduce naturally occurring acids and create an issue with over-ripeness or “flabbiness”? You’d hope that our talented winemakers will find ways to adapt and adjust their viticultural practices, but what about the cool climate producers – could climate change actually enhance the quality of their shiraz offering?

The popularity of shiraz is likely a product of its robustness, spice and often sweet finish. Sometimes described as a “fruit bomb in a glass”, the typically high level of alcohol ensures a warmth to the finish that compliments a syrupy mouthfeel. But producers in cool climate regions generally focus less on fruit forward styles and allow their shiraz to be an expression of terroir. The challenge for winemakers in colder regions is ripeness – without enough sun and heat to ripen the fruit, their grapes struggle to make shiraz that will be commercially successful.  And somewhat ironically, that’s where global warming might actually be a good thing for parts of the wine industry – imagine cool climate regions that stay cold in winter but enjoy somewhat warmer conditions during summer. Might the wide daily diurnal temperature range mean even better shiraz in places like the Great Southern (WA), Orange (NSW) or Yarra Valley (Vic) or Mornington Peninsula (Vic)?  What could climate change mean for some of my favourite cool climate shiraz, like Giaconda Warner Vineyard Shiraz (Beechworth), Seraphim Heathcote Shiraz (Heathcote) or Scorpo “Old Vines” Shiraz (Mornington Peninsula)?

In Victoria, the Yarra Valley has always been one of my favourite regions.  Their chardonnay is superb and their cabernet, sublime. But I wonder what higher temperatures might do for their shiraz?

Over at Paynes Road in Seville, John and Josie D’Aloisio have spent over 40 years as agriculturalists and these days are making terrific examples of nebbiolo, sangiovese, tempranillo and barbera as well as mainstream cabernet and shiraz styles. Their No 8 Shiraz has always been a stable star (at least in my eyes) with its forwardness of fruit, black cherry and mocha characters, white pepper and spice and the tannic overlay on the finish. But imagine if we could add richness, mouth filling and ripeness to the descriptors? Increase growing season highs by two degrees and I wonder what we might taste in the glass? The 2012 Seville Hill No 8 Shiraz ($60) is currently quite light and bright in the glass and more of a “polished” or “elegant” style. It’s sibling, the 2014 Reserve Shiraz ($40) is similar in structure but perhaps softer in its tannins and lighter on the palate. I’d love to combine the elegance and sophistication of these wines with the warmth and ripeness of a McLaren Vale syrah. Might climate change make that dream a reality?

Yarra Valley shiraz is undeniably good – think Yarra Yering Carodus or Levant by Levantine Hill – but future generations of wine lovers might find themselves sampling shiraz from the region that could be unrecognisable to modern day aficionados.