Across the world, winegrowers recognize the extra quality that older vines can bring. So on a recent visit to New Zealand, I was curious to check on the state of Pinot Noir, in a country where the majority of vines have been planted within the last decade.
Central Otago is quite a new region—
A test case for examining the effects of vine age in Pinot Noir. “Our oldest vines now are 21 years old, and we have cohorts going [further] back,” says Nigel Greening of Felton Road in Central Otago.
“We see a fairly profound change around the 10- to 12-year point. The vines respond less [to variations in climate]; their roots are deeper; there is greater inner strength to them. The wines show less variance; they are less fickle.”
Greening had charted a graph of vine age in his Bannockburn Pinot Noir, which draws on fruit from a range of vineyards. “[Vine age] was at a relative high point when I came to the winery in 2000, because it was relying almost entirely on plantings made in 1991, ’92 and ’93,” he reports. “Then, as we started to expand and plant new vineyards, the vine age progressively dropped. It took us until 2009 to get back to a new high point. For our Bannockburn Pinot Noir, the average vine age is now about 12 years. A lot of producers are in a similar situation across much of New Zealand.”
Working in the North Island region of Martinborough, Steve Smith of Craggy Range recently opened 10 vintages of Pinot Noir from Craggy’s Te Muna Road vineyard.
The wines showed a clear progression, with an added dimension in the latest vintages, something that Smith attributes to vine age. “The key to establishing vineyards is encouraging the vine to send roots way down,” he says. “We started seeing the place [Te Muna] shown in 2008 with eight- or nineyear- old vines, and every year since we have seen more expression of place.” Smith thinks you can make good but not great wines from young vines, and also that fruit off older vines requires less winemaking intervention. “The first 10 years are dominated by fruit rather than the place. From 2008 onwards we have had to do less to the wines.”
In Burgundy, there are no particular rules about when young Pinot vines can be included in the blend of village, premier or grand cru vineyards. It’s up to the grower. “Producers take varying views,” says Burgundy expert Jasper Morris. “Some do trial blends and include a few barrels of young in with the old if it improves the overall wine, and declassify the rest. Some would wait 10 years and some 20 for grand cru.” Jeremy Seysses of Domaine Dujac thinks it takes as long as a quarter of a century for a vine to show its best. “For me, a vine seems to enter its prime around 25 to 30 years of age,” he says. “Young vines can certainly express terroir, but the expression is perhaps not as strong, not as consistent and usually, there is something that falls a little short on the texture front.”
So what is it about vine age that makes such a difference?
There are a couple of plausible theories. The first is that time is needed for the root system to thoroughly interrogate the underlying soil.
A mature root system will reach down into the subsoil or bedrock, and through mechanisms that are still a matter of debate, will then be able to express the terroir more effectively.
This could be through establishing a steady, consistent, but moderate supply of water.
Or it could have to do with the chemical composition of the subsoil and particular nutritional inputs. Either of these options would explain why it takes a while for Pinot vines to begin to express their particular terroir in consistent ways.
Older vines also generally have larger carbohydrate reserves in the trunk and root system, ensuring a better start to the growing season before the vine reaches the point that it is supplying all its needs through photosynthesis.
Older vines also seem to settle into a better natural balance, with modest vigor in the canopy and modest crop levels. (That is, when they are planted on appropriate vineyard sites, and are spaced and trellised in the right way.) Pinot Noir is one variety where you can’t simply cheat on yields.
This last suggestion chimes with the observation that the first couple of crops of young vines are often better than the next few,
the idea being that the young
vine is in better balance than a more vigorous adolescent
vine that hasn’t properly settled down.
Then there is the fact that vines in the best sites, performing well, are less likely to be replanted even when their yields start to drop, and so are allowed to become old: a confounder, if you will.
But while vine age seems to be working in favor of New Zealand Pinot Noir, there is a cloud on the horizon. It’s called grape leafroll virus, and it necessitates replanting vineyards, often as they are just beginning to hit their stride. “Virus is becoming a bigger and bigger issue,” says Smith. “It’s the greatest threat to New Zealand making wines from old vines, especially for red wines.”
Grapevine leafroll–associated virus type 3
(GLRaV-3a) is a huge problem for viticulture generally. It is spread through vineyards by insect vectors, principally mealybugs. Virus affected vines produce low-quality wines, especially for red varieties. It reduces yields up to 40 percent, delays maturation of fruit (a particular problem in cool climates), and reduces the life span of the vine. The virus is a well-known problem in South Africa, but also in New Zealand and California. Once a vine has been affected, there is no cure.
For red varieties, virused vines can be spotted visually in the vineyard because late in the season the leaves become red, with green veins still visible. For white varieties, it is less obvious: There is a slight chlorosis (yellowing of the leaves). In both red and white varieties, the leaves roll downwards, and there is disruption of the phloem, the plant’s vascular system that circulates sugars. If just a few vines in a vineyard are infected (and this can be determined by using an antibody based diagnostic test called ELISA), then it is possible to pull just these affected vines out, a process called “rogueing.” The soil needs to be cleared to a depth of one foot because old root material can host the bugs. Once the infection rate exceeds 20 percent of a vineyard, most growers choose to pull out all the vines, removing all the roots and then, once the ground is clear, replanting with certified virusfree vines.
If there are infected vines in the vineyard, then the virus spreads with any mealybugs as they move from vine to vine. So growers work to reduce the mealybug population, as well as to spot and remove infected vines.
With New Zealand’s wine industry actively pursuing a sustainable approach, this could be challenging. However, the sustainability regulations are pragmatic, and allow the use of certain insecticide sprays in order to control mealybugs. For organic or biodynamic growers, this isn’t an option.
While the virus has likely been in New Zealand since the 19th century, it has become a particular problem only recently. “Rapid spread began with the boom in vineyard plantings starting in the 1990s,” says Dr. Simon Hooker, general manager for research at New Zealand Winegrowers. “The disease was noted as causing declines in fruit and vine quality by the early 2000s, especially with regard to the production of premium red wine styles.” In response, New Zealand Winegrowers began working with nurseries to develop the guidelines that would eventually become the Grafted Grapevine Standard, and in 2008 began the Virus Elimination Project.
“The extent of area affected by GLRaV-3 is something we are researching,” says Hooker.
“We don’t yet have a definitive answer.” But he says that the project has already achieved considerable success in the first two pilot regions of Martinborough and Hawke’s Bay.
“Many growers in those regions have already achieved the initial goal of reducing infection incidence to below one percent in their vineyards—something they would not have believed possible five years ago.”
So a mixed story is emerging. On one hand, New Zealand’s best vineyards are producing increasing multidimensional, detailed pinots. And on the other hand, leafroll virus is threatening to rain on this parade by preventing existing plantings of the grape from reaching full maturity. ν
