Does latitude matter?

September 21st, 2009

Does latitude matter? Annotated from Google Maps. (latitudes given are rough approximations)

Does latitude matter?

As wine growing culture in a particular region evolves, it sometimes becomes apparent that what has been grown for a long time is just not going to cut it anymore. The interplay between climate (rainfall and temperatures), soil, a variety’s productivity, the character of its fruit does not always yield a desired quality level in the finished wine.

So, through the initiative of individual growers, as part of an organized effort or by official mandate, different cultivars are brought in to a particular region with the hopes of elevating the quality of a regions wines. This is the essence of Cépage améliorateur.

Trying different varieties, growing techniques and locations is at the core of enological innovation. While it has been generally accepted that successful, world-class viticulture is not achievable beyond the 50th parallel (the northernmost vine plantings are said to be in Sweden, north of the 59th parallel). Southern England, straddling the 50th parallel benefits from both climate change and the tempering effect of the English Channel.

A large body of water mitigates a cold climate and it cools a hot one. It is no surprise, then, that the foremost wine growing regions in the U.S. are on the Pacific coast. That statement is not intended to diminish or disparage the East Coast, the Finger Lakes or Niagara Peninsula. My daily pondering is centered on the question: is heat summation comparable to the region of a variety’s origin enough (assuming similarities in soil, etc).

I want to know: does latitude matter? One only has to follow the lines of latitude around the globe to see where the leading European and American regions sit:

Champagne: ~48.5° – Canada/US Border (Finger Lakes & Niagara)
Burgundy (Austria): ~47° – Seattle
Bordeaux: ~44° – mid Oregon
Rhone: ~43.5° – middle of Oregon
Southern Italy (Central Spain): ~40° – Eureka, CA
Napa – ~38° – central Portugal
San Francisco: ~37.5° southern Portugal
Los Angeles: ~34° – Casablanca, Beirut

Certainly, California Pinot Noir is different from Burgundy, which is different from Oregon or new Zealand Pinot Noir.

Because the earth’s axis of rotation is tilted at 23.5°, regions further from the equator receive not only different amounts of total annual sunlight, but this difference in the angle of incidence of the sun’s rays results in greater warming of regions closer to the equator. To compensate for this, most American vineyards are planted in coastal regions.

However, I cannot help but wonder if the difference in the angle of incidence affects the physical nature of the light reaching vines: Are the frequencies of light reaching the planet’s surface at different latitudes different? If so, does this have an appreciable effect on the cultivars that do best at a particular latitude? If that is true, should latitude be part of terroir? Finally, should a region’s varietal selections be made based with latitude in mind?


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6 Responses to “Does latitude matter?”

  1. Ron McFarland Says:

    I think you are right that latitude does influence the outcome of some grapes. Crawford Brown at Bannock Brae Estate in Central Otago talks about how the latitude, daylight and earth tilt influence grape growing in Central Otago.

    The video is insightful.

  2. Thomas Pellechia Says:

    If by “foremost” you mean empirically ranked by reputation, then I agree with use of that word to describe the Pacific Coast wine industry in the US.

    On the questions you ask in your last paragraph, I’d answer to all of them: probably.

  3. Is There Any Remedy for Anxiety? | Panic Attacks Blitz Says:

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  4. Dylan Says:

    Latitude certainly plays a part, I just wouldn’t overemphasize its role in successful wine making. Being on the same-parallel as the top Bordeaux in France doesn’t account for the climate or soil you might experience at a separate longitude. Hence why the spot where the 44th meets the Atlantic Ocean hasn’t been opted as a place for growers just yet.

  5. Nathan R. Carlson Says:

    I just came across this – my thought is that most everything in nature is very sensitive to photoperiod. It can influence growth and hormonal triggers in many animals – telling them when to breed, ovulate, lay eggs, fly south, etc… Plants, which rely on the sun for their metabolism are even more tuned in to length of day & intensity of light.

    I can’t speak to exhaustive knowledge of the mechanisms, but I have made wine from Pinot Noir in Oregon, Carneros, and the Central Coast, (as well as having visited many of the other main growing regions for this variety throughout the world,) and can tell you that the vines look and behave completely differently depending on location. There are other differences in play in these environments, for sure, but I suspect that photo-period has a great amount of impact.

    For instance, Pinot in Oregon will start to show lignification of the canes and rachis shortly after veraison, while in the Edna Valley and Santa Barbara County, it may take until harvest to see the same degree of browning of these structures. Seed ripening is also affected to some degree. And the order in which varieties become ripe on the same site can be completely reversed depending on location.

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