Monday, December 7, 2009

End of the Golden Age in Wine?

For the past 20 years, we’ve enjoyed a golden age in wine making…and drinking. Around the world, poor vintages have been rare. Much of the credit is due to revolutionary improvements in both viticulture and vinification techniques. Even more so, many winemakers have benefited from warmer temperatures, which produce riper grapes with more flavours and sugars.

Of course, these warmer temperatures are part of climate change. For many of us, climate change is an abstract issue. One aspect of climate change, global warming, sounds benign or even desirable to Canadians heading into winter. But climate change is much more than a warmer planet; it also brings us wider fluctuations and increasing extremes in temperatures, precipitation, wind, and other climatic elements.

A recent article in the French magazine, Science et Vie, got me to thinking about what could happen in wine making if climate trends continue. What further developments and coping measures might we see?
  • Some Like It Hot? As grapes ripen in warmer temperatures, they quickly produce more sugar, which converts to alcohol during fermentation. A German wine researcher estimates that for every 2.4°C increase in the average temperature in August, the alcohol level in wine increases by 2 percentage points. Wines from the world’s warmest regions are now often in the range of 14-15% alcohol. Spain has produced a wine at 17%. Will discerning consumers want these big, fat, hot (alcoholic) wines?
  • Increased Frost Damage: In many areas, budding on vines starts 2 to 3 weeks earlier than it did 30 years ago and that trend will continue. However, temperatures now fluctuate more widely during the earlier budding period, increasing the risk of a killing frost.
What will wine producers do to beat the heat…or frost?
  • Varietal Changes: Some varietals that ripen early, such as merlot, may become less viable and popular, later-ripening varietals, such as syrah, more so. But in France (for example), where the appellation regulations limit where winemakers grow which varietals, winemakers cannot simply rip up merlot and plant syrah. One “fortunate” winemaker in Bergerac has decided to rip out all of his merlot vines (45 percent of his vineyard) and replace it with two other permitted varietals, Cabernet Franc and Malbec. Why? Because the sugar/alcohol level now gets too high in merlot before the grape reaches full maturity (not enough flavour and tannins). The challenges for some of the best Pomerol (Bordeaux) winemakers that grow predominately merlot are enormous. In contrast, other Bordeaux wines, such as Médoc, that grow the later-ripening Cabernets and Petit Verdot, may become better. Even so, Bordeaux, which relies on blending up to five different grapes to make its wines, is in a much better situation than regions that make wines from single varietals, such as Burgundy, Alsace, and Loire. If their varietals can no longer thrive in the local climate, knowledge and reputations that took centuries to build will be in the dustbin of history. Any country that has powerful wine regulators will be caught between a rock (climate change) and a hard place (inflexible rules).
  • Shifts in – and within – the Wine Producing Latitudes: Today, the world's wine producing regions are between the latitudes of 30° and 50° in both hemispheres. With an increase in temperature, wine production may extend beyond the 50th parallel, and is increasingly tenuous at the 30th parallel. Within the last 3 years, both Denmark and Sweden increased their efforts in winemaking. In the world’s existing wine producing areas, it’s the ones at the geographic edges, such as Ontario and British Columbia, that will benefit from warmer temperatures. Another example: some of Australia’s best wines are now coming from its most southern region, Tasmania.
  • Shifts in the Wine Producing Altitudes: Another way to beat the heat is to move vineyards to higher altitudes. For example, the Catalan producer Torres is buying properties in the Pyrenees.
  • Shifts in Hillside Exposures: For several reasons, hillside vineyards produce the best wines. More often than not, winemakers plant these vineyards facing south or west, to take advantage of the afternoon sun. Vineyards might be re-oriented to northern or eastern exposures for exactly the opposite reason: to reduce over-exposure to sunlight.
These 3 shifts – in latitudes, altitudes, and exposures – all mean moving vineyards to new locations. But the conventional wisdom is that it takes 3 generations to produce good wines in a new geographic area. Most of us won’t live to drink the great wines of the Pyrenees!
  • Less Frequent, But More Intense, Rain: If you’ve seen An Inconvenient Truth, then you've seen that there are more areas in the world that receive the same annual amount of rainfall, but the rain falls less frequently yet more intensely. What’s the significance? When the intense rain does fall after a long dry period, the topsoil erodes, making it even more difficult for the subsoil to store any moisture. The damage to the premium hillside vineyards is even greater. This phenomenon is increasingly common in southern Europe (Spain, Italy, Greece, and southern France), California, and Australia.
  • More Irrigation: Even if overall annual rainfall remains the same, there are key moments in the growing season when water is critical. If rainfall becomes less frequent, then irrigation becomes attractive. Advantage here to the New World, where irrigation is much more common. Much of the EU frowns on irrigation and overcoming those attitudes could be difficult. In either case, vineyard irrigation places even more demand on scarce water resources.
The potential loss of the wines we enjoy today is not the most catastrophic consequence of climate change. But the measures needed to cope with it are fascinating and illustrate the new challenges that winemakers face.

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