Andrew Jefford feels the chill wind blowing down the Rhône valley and asks if the vines enjoy it more than the humans do.

Introducing the mistral wind

It was grey and overcast when I climbed aboard the train for Avignon, and barely brighter when I got off. When I reached Châteauneuf du Pape, though, the horizon to the north was clearing, and the brooding silhouette of Mont Ventoux began to loom. Mid-morning came; the cypress tops swayed.

By lunchtime, the sky was brilliant blue, and the spring sunlight glittered as if filled with tiny ice particles. The air grew brisk, agitated, lively, alert; there was a new drama in the scene. Every stone in the vineyards took on shape, form and detail, as far as fallible eyes could reach. Light filled every tree, too, as each leaf was in movement. It was a storm of light.

I’ve been thinking recently about the possible influence of wind on terroir, and had noted how often the mistral was written about as a major hazard of viticulture in the Southern Rhône. This, I felt, just had to be wrong. The glory of Châteauneuf as a wine – its amplitude and breadth, its concentration, its extravagance of flavour – owes much to its extraordinary combination of sunlight and wind. Why not take a day in Châteauneuf to talk to growers and understand the effects of this wind a little better? By chance, the mistral chose to charge in and clear the midday sky while I was there, as if to illustrate the theme.

First, though, a brief description of what the mistral is, and why it happens. When high pressure in the Bay of Biscay coincides with low pressure in the Gulf of Genoa, a current of cold air is drawn from the north of France southwards to the Mediterranean. This air is funnelled down the Rhône valley, running high above the vines in the northern Rhône, but swooping down to bushvine level through Châteauneuf and the southern Rhône. The near-hurricane-force record was logged at 116 km/hour on April 6th 2003 (a hurricane is categorised as 118 km/hour or more according to the Beaufort scale).

“For me,” said Catherine Armenier at Domaine du Marcoux, “it’s Dr Mistral. It has a hundred times more advantages than disadvantages. It’s truly a part of the terroir here, and Châteauneuf just wouldn’t be Châteauneuf without the mistral.” Consultant Philippe Cambie pointed out that it makes organic cultivation relatively straightforward, and “gives you savings of at least 50 per cent of treatments” compared to other regions without the mistral. “It’s a privilege for us,” said Jean-Pierre Usseglio, “even though it’s difficult for us to put up with sometimes.”

Human discomfort may account for much of this wind’s sometime’s villainous reputation. Animal perception of the mistral, after all, is very different from plant perception. We feel a drop of 1°C for every 10 kilometers per hour of wind, so a winter day of -3°C can feel like -11°C or more in a strong mistral. “In some years,” says Catherine Armenier, “we don’t go out for 15 days. Even in August, if there is a celebration or something in the evening, we’re all wearing thick jumpers and the tourists are freezing.” “You can handle one or two days,” says Harry Karis, author of the magisterial The Châteauneuf du Pape Wine Book (which contains the most comprehensive collection of data on the mistral at present in print in English). “After three to six days you get a bit sad, and after that you get depressed. You hear the cracking of the ceiling, the whole building is moving … not just outsiders like me [he now lives in Châteauneuf], but the locals, too. You can see it in their faces.”

There are, of course, some genuine viticultural drawbacks to the mistral – Christophe Sabon of Clos du Mont-Olivet calls it “a coin with two sides”. The worst risk is when the shoots are about six to nine centimetres long (and April is historically the most mistral-vulnerable month), as the wind can then snap the shoots, provoking harvest losses. You can use attaching wines above the bush vines to hold the shoots in place (as at Ch La Gardine), and in any case shoots will usably re-grow, provided you are prepared to harvest their fruit later than the rest. But Catherine Armenier is philosophical about the losses. “I think if you have broken branches in spring it’s a little like making a sacrifice, in order to have something better later on.”

Other disadvantages? There don’t seem to be any, other than that human discomfort. A high wind at flowering doesn’t necessarily mean crop-setting problems. Grenache (the main grape variety in Chateauneuf) is coulure-prone, it’s true, but this tends to be for mysterious reasons, and can happen in calm periods as well as windy ones. High wind at the very end of the season will mean a loss of juice, as water begins to evaporate through the berry skins – but that may be a factor behind the ravishing, palate-seducing concentration you find in great Chateauneuf, and thus a positive terroir trait.

The mistral is especially good for drying the vineyards after the heavy downpours to which the region is prone – “50 to 60 mm of rain,” according to Philippe Cambie, “will dry in 3-4 days if there is a mistral afterwards.” The mistral-after-rain phenomenon meant that both 2007 and 2008 were propitious vintages, whereas the colossal rains of September 2002 were rendered even more catastrophic by the fact that no mistral came afterwards.

Not only is the mistral very good at keeping fungal diseases at bay, but it’s also good at repelling insect pests (especially grape moths) – since they don’t like being hurled around in the wind any more than humans do. Jean-Pierre Usseglio says he has always noticed that there are fewer insects in plateau vineyards (those most exposed to the wind) than in vineyards on slopes.

In the winter, the mistral will keep frosts at bay, and Usseglio also says that he prefers to work the soils when there is a mistral, since the wind “lightens and opens up the soil”. Once the goblet vines have a canopy, the leaf movement provoked by the wind provides ideal intermittent sunlight exposure as well as prophylactic ventilation. The mistral evidently mitigates summer temperature extremes, and dramatically so. All of the growers confirmed, too, that the wind (and the consequent drop in air humidity – it fell to an astonishing 13% in 2003, according to Harry Karis) encourages the vine to send down deeper roots in search of the moisture that they are losing in transpiration. Deep roots are a hallmark of most great vineyards.

Châteauneuf, finally, has few rivals in France in terms of its old-vine patrimony: it’s a viticultural ‘blue zone’, if you like. Many vines here have 100 years of mistral in their memory bank. If they weren’t happy with the health benefits provided by that tearing wind — no matter what the humans may think – they’d have died decades ago.

Tasting the mistral

Can you ‘taste the mistral’ directly in Châteauneuf? No: every year has some mistral, and there are too many other inputs into a particular wine’s character to assign any preponderance to wind. Philippe Cambie did risk suggesting, though, that lots of mistral encourages flavours of prune, fig and orange peel, while less mistral gives crushed strawberry, raspberry and cherry flavours.

According to data collected by CIRAME, the local agro-meteorological organization, there are on average 39 days of strong mistral (more than 57 km/hr) in Avignon, with 1995 and 2010 being the windiest recent vintages (51 days each). The least windy vintages, by contrast, were 1997 (31 days), 199 (29 days) and 2012 (31 days).

Just for fun, then, here is a comparison between two ambitious Châteauneufs, one grown in windy 2009 (41 days of mistral) with one grown in less windy 2012 (31 days of mistral).

Pierre Usseglio, Cuvée de Mon Aïeul, Châteauneuf du Pape 2009

Almost all Grenache, and almost all aged in cement, this is a hugely attractive, gentle giant of a wine in which you can, perhaps, read the trace of the wind (and the warm vintage) in cooked rather than fresh red-fruit notes and a glowing, sweet-toned concentration. Mushroom, truffle and tobacco notes are infiltrating the fruit as the years pass, giving an elegance you might not have anticipated in youth, and the soft yet substantial tannins are so stealthy they might almost pass unnoticed, though they bring a fine drinking balance to the wine. 95 points (/100)

Clos St Jean, La Combe des Fous, Châteauneuf du Pape 2012

A blend of tank-aged, centenarian Grenache from La Crau with smaller amounts of wood-aged Syrah, Cinsault and Vaccarèse, this is a darker wine than Mon Aïeul with fresher, creaminer black-fruit scents and flavours which seem almost pert, bright and vivid. There’s more fresh fruit and wild flowers on the palate – but a trace of honey, too. It is neither notably more acidic nor more tannic; what’s different are the flavour allusions and the way that the different elements are gathered together in the wine. 95

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