Champagne is considering sweeping changes to its viticultural model in an attempt to adapt to climate change. Giles Fallowfield considers the proposals, from expanding vine spacing to planting new grape varieties.

The Champagne economy has faced some major challenges since the dawn of the new Millennium. For most of the noughties, keeping up with increasing worldwide demand looked like being the most difficult to address. Revising the appellation to do this, by increasing the area under vine, was never going to be a simple task. But the financial crisis of 2008 and the steep initial drop in demand, followed by a levelling off at around the 300m bottle mark, has made this ‘revision’ – the Champenois don’t like anyone calling it an expansion of the vineyard – considerably less urgent. It may never happen now.

Coronavirus will surely bring consumption down further in the short term, even though we have never needed a glass of cheering fizz more, but the greatest challenge that Champagne has to address is how to adapt to, and in the longer term deal with, climate change. This threatens its very existence, not its short-term consumption.

Even if it does succeed, it’s highly likely the wine that future generations call Champagne, will be different to what we are currently drinking, possibly radically different and produced partly or entirely from new grape varieties. The Comité Champagne (CIVC), the region’s governing body, has been experimenting with and developing new varieties since 2010.

Evidence of the need for change has been mounting: Warmer and sunnier summers, with some extremes of temperature reached – notably during the last two growing seasons; harvests starting on average 18 days earlier over the past 30 years; potential alcohol increasing on average by 0.7% volume and total acidity dropping 1.3g H2SO4/l. And although the CIVC also says that average rainfall is unchanged at 700mm a year, that too has become less predictable. In the summer of 2019, rainfall was below average in June and August and significantly down in July, when just 15.1mm fell on average, compared with the normal monthly average of 57.9mm, while there were 306.9 sunshine hours, well above the normal average for July of 236.2 hours. (see table below showing temperatures and rainfall in the summers of 2018 & 2019).

Table A: Temperatures, rainfall and sunshine hours in July (first table) and August 2019 (Source: Le Vigneron Champenois)

The average temperature has risen by 1.1degC and while that may not sound that much, the effect of the warming climate on France’s most northerly vineyard, located just south of the 50^th parallel, has been dramatic. In 2003, the harvest began on 18 August – before that you had to go back nearly two centuries to 1822 to find the previous earliest, when grape picking began on 20 August. Since then we have had four further August harvests starts in 2007, 2011, 2015 and 2018 and a run of other warm vintages. And the 2020 harvest is the earliest ever.

During the 2019 harvest there were three heat spikes with the temperature reaching 42.9°C in the Vitryat village of Glannes to the south-east of Châlon in the last week of July, the highest ever recorded in the Champagne region. There were on average 23.13 days when the temperature was above 30degC over the summer in 2019, which is barely less than the 24.69 such days in the summer of 2018, which produced the earliest ever harvest start on record on 17 August.

In response, last June (2019) the Comité Champagne produced a 15-page document Climate Change: Adaption in the Champagne Region setting this out. It covers a lot of ground from outlining some of the immediate impact climate change is having on the growing season, through reducing Champagne’s carbon footprint, developing new grape varieties, adapting viticulture and winemaking and more widely introducing sustainable viticulture.

While the Comité recognises the positive effect that warmer summers are having on the general quality of the musts, it also notes the diurnal range in temperatures, seen as helpful in preserving freshness prior to the harvest, has diminished. Partly as a result of more August harvests.

Here we are looking mainly at the short to medium term changes to viticulture, some proposed and others already being introduced, while touching on the longer term work investigating the performance of ‘suitable’ new varieties (see section below, entitled: Programme to develop new grape varieties). The dossier lists four areas where changes can be made now under the headings ‘soil management’, ‘growing practices’, ‘grape ripening’ and, more controversially, ‘wider spaced vines’.

Under growing practices, it talks about managing foliage height and density, to counteract warming climate. And this is already happening in the vineyard. Heat wave scorching (échaudage) of the grapes, resulting in some volume loss has been an issue during several harvests since it first came to the fore in the heatwave summer of 2003. And unsurprisingly, given there were three significant heat spikes in June, July and August in the summer of 2019, this again impacted many producers.

Michel Davesne chef de cave at Deutz estimates that between 10-20% of the crop was lost in some Pinot Noir plots as a result of the three summer heatwaves. Florent Nys chef de cave at Billecart-Salmon says the sun burned about 20% of the grapes in the two heatwaves of July and August while Michel Drappier reports that in Urville in the Côte des Bar, “the excess summer heat combined with the drought, accounted for a 15% crop loss”.

Speaking after the 2019 harvest about how producers need to adapt to heat extrêmes, Charles Philipponnat CEO of the eponymous house, whose vineyards were also hit by scorching in the hot weather in the run-in to the 2016 harvest, says “things like adopting a higher canopy have already been implemented and may be pushed further, along with wider space between rows.” And wider spacing between rows has, it seems, become the preferred option for the vineyard the Comité Champagne is promoting and to which it gives most prominence in its climate change review.

Work on this started back in 2005 when INAO authorised the plantings of a dozen hectares of more widely spaced vines on an experimental basis in 17 different plots located around the Champagne area. This work had environmental aims – like reducing the number of treatments needed – as well as examining planting density options. In these experimental plots the spacing between rows varied between 1.8m and 2.2m and the space between the vine stocks, on the row, between 0.9m and 1.2m. Density varied between 4,000 and 5,500 vines per hectare, compared with the traditional figure of 8,000 vines per hectare. A first evaluation of these plots showed that vines so planted are: slightly less susceptible to spring frost (an important point as earlier bud burst is increasing the incidence of damage by spring frost, despite a drop in the number of frosty nights); that grassy strips in between rows are easier to maintain; mechanisation is simpler; and that resistance to water shortages is improved. Wider rows also enable [higher] acidity to be maintained in the grapes.

If the new wider rows (assuming this proposal becomes enshrined in the Cahier des Charges for the AOC) were only adopted when replanting was due to take place anyway, this change would come into effect slowly over a very extended period, perhaps 70 years or more. The current the rate of replanting in Champagne is fairly low (see Table B below), typically between 400 and 500 hectares in any three-year period, as older vines are dug up when they become less productive. But as the CIVC’s Thibault Le Mailloux explains, “The wider gap could be created by uprooting every other row in still productive vineyards] which would considerably accelerate the change-over”.

Table B: The area of vineyard being re-planted each year (2017-2019)

Source: CIVC. Note: The difference between the figures for the ‘planted area’ in these three years is accounted for by producers who don’t immediately replant their vineyard in the spring after grubbing up the vines. The CIVC’s technical department actively encourages growers to wait at least one year between grubbing up and planting, for the land to recover. And since 2017, has compensated growers that do so by allowing them to take some wines out of their reserves, 8,000kgs/ha in the two years when this vineyard is not producing any usable grapes (thus they only lose one out of three years, when the parcel is unproductive).

Significant savings

There are additional advantages that make the ‘wider-spaced vines’ solution more compelling. One of the main ones is that the wider gap will make it possible for grape growers to use the more basic and cheaper type of vineyard tractor to plough the grasses and herbs growing between the vines. As ploughing is the only obvious solution to controlling the cover crop between rows in the new no-herbicide era that is fast approaching – Champagne is committed to wholly banning herbicides by 2025 – this is particularly important. Currently the only options in the typical gap between rows, which may be no more than 1.5metres wide, are horse drawn ploughs or the tall, specialist ‘enjambeur’ style tractor, that straddles the vines.

These tractors cost around €200,000 each which is about five times as much as models used more widely in France’s vineyards, so this development would make mechanical ploughing far more affordable for the smaller scale grape growers who are in the majority in Champagne.

Le Mailloux also notes that wider rows will also make any necessary spraying easier and more accurate, which will reduce the volume of spraying, saving money and helping to protect the environment, very much in line with Champagne’s viticulture raisonnée goals. And there is evidence from their trails that acidity in the grapes is preserved for longer in the wider rows, though he says this could be partly because of the greater use of cover crops between the rows. Because the vines will be trained higher, the wood will be further off the ground making the vines less susceptible to frost at the start of the growing season.

Wider rows and the generally less dense planting contemplated will also bring yields per hectare down, which may still potentially be an issue for grape growers who are paid for their grapes by the kilo. However, in an era where worldwide demand for champagne is lower, the fact that the maximum permitted yields in recent harvests have already been adjusted downwards to a level that could reasonably still be achieved (10,200kgs/ha rather than the 13,000-plus that could comfortably be reached in more abundant years), makes this less of an issue currently.

Louis Roederer, one of only four players owning more than 200 hectares of Champagne vineyard, has had experience of both higher and lower density vine planting. As head winemaker Jean-Baptiste Lécaillon explains. “We have been among the first in Champagne to experiment with lower density plantations, our first trials started in 1980. We moved in that direction taking into account our own experience in California’s Anderson Valley, where we were planted in low density and we wanted to know how such a plantation would work in Champagne. In early 2000 the first conclusion from this trial, supervised by CIVC, was negative, mainly because of too low a density [of planting].”

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But it the new [low density] trials run in conjunction with the CIVC, in which Roederer has one of the largest blocks, Lécaillon reports “we had quite a good experience and we agree with their conclusions. It’s an interesting solution, in certain specific conditions that need to be identified.”

However, in the 240-hectare Roederer Estate for its own replanting programme, that started in April 2020, they have adopted a higher, not lower, density of planting. “We’ve now decided to go from the classic 8,300 vines per hectare to 10,000-11,000 vines per hectare in all our replanted vineyards.” Essentially, they are doing this to achieve: “a lower yield per vine, while the higher canopy [also adopted] will help cast more shadow on the bunches.”

Lécaillon explains the apparent contradiction (between supporting the CIVC trialling of lower density vineyards and the agreeing with the Comité’s conclusions, but adopting higher density planting itself): “Louis Roederer is first [in effect] a vigneron, relying on the strong resilience of our chalky soils. Our approach in more Burgundian, in a way. Most of our vineyards are grand cru, mid-slope, with lots of chalk and little topsoil, so not much vigour. We use massal selection of Pinot Noir and Chardonnay based on low vigour, low fertility and small bunches of small berries.”

They stopped using herbicides 20 years ago, mechanically till all their soils, don’t use any fertilisers apart from bio-dynamic composts, 122ha of the estate is certified organic and he says, “we tend to favour old vines, with an average of 40-years plus in the Crystal estate vineyards. As a result, yield per vine are already 30% less than you could achieve with other clones and younger vines.”

It’s important to note that, “The more vines you have per hectare, the more consistent your yields are one year to another, they become less dependent on varying weather conditions. There’s an old vigneron’s expression: ‘The fewer vines, the more sunshine and climate in the wine; the more vines, the more freshness and soil’ and it’s true.”

Clearly the wider spacing will not be suitable for every grower in Champagne, nor every location. But such spacing would also work well with the other ‘soil management’ and ‘growing practices’ recommended in the CIVC Dossier, like introducing more cover crops and ploughing.

Looking further ahead, wider spaced vines would also make mechanical harvesting a realistic possibility on the less steep vineyard slopes. The era of pickers coming to the Champagne region each harvest from other European countries may be over. With the current Corona-Virus lockdown it is certainly under threat and it seems, enough French pickers aren’t available. This could be a major problem in the approaching 2020 harvest.

In any case, the unpredictability of the harvest start has already become one of the big additional headaches that climate warming has brought to Champagne. It’s now far harder to select in advance the best dates to begin picking in each cru. The ripening process used to be more predictable, with the sugars and potential alcohol developing in a steady, linear fashion. With good planning, it was relatively easy to give suitable notice of perhaps a week, to the teams of pickers that flood into Champagne to pick the grapes each autumn, from countries like Poland. But the heatwaves experienced over the past decade and particularly during the past two harvests, have made this much more difficult.

Much more accurate weather forecasting has become critical, not just for calculating picking dates, but also for assessing when to treat against diseases, like botrytis, odium and mildew, during the growing season. Especially as there is pressure to reduce such treatments as much as possible.

The textbook model of 100 days between flowering and harvest has been out-of-date for some time. On average it’s now dropped to 92 days. But that’s not really the issue, it’s the unpredictability of the speed of ripening. Le Réseau Matu system which sees testing taking place at over 450 sites spread over the appellation, shows how fast sugar and therefore potential alcohol in the grapes, is developing from around mid-August. A normal rate of ripening would see sugars rise by about one degree per week. When the first readings were taken in 2019 on 19 August, the average sugar levels were already high with Chardonnay at 5.1% vol, Pinot Noir, 6.4% vol and Meunier at 5.8% vol.

The arrival of the third heatwave in Champagne in the second half of August (temperatures rose rapidly from around 18 August to reach a peak 10 days later) saw potential alcohol increase dramatically in just one week. When the second sampling was taken across the appellation on 26 August, it showed sugar levels rising by + 2.6% vol in the case of Chardonnay (to 7.7), + 1.8% vol for Pinot Noir (to 8.2); and + 1.9% vol for Meunier (to 7.7).

“The decision on when to start picking was tricky,” says Alice Paillard, CEO of the eponymous house, “since maturation suddenly increased very quickly in the last four days of August, gaining in some areas more than 2.5 degrees in six days, which is absolutely unheard of. A more normal rate [in Champagne] would be to see sugar advance one degree in a week, while 1.5 degrees is fast.”

To make matters more difficult, grapes showing relatively high potential alcohol levels of 10deg° or even slightly higher, were still not showing phenolic ripeness. Rodolphe Peters who runs grower producer Pierre Peters in Le Mesnil-sur-Oger notes that “this year there was a disconnection between sugar levels and phenolic ripeness,” you had to wait to achieve the latter and keep tasting the grapes. The average potential alcohol level this year (2019) [from holdings he has in Le Mesnil, Oger, Cramant and Avize] was a high 11.52deg.

“We decided the harvest dates not just on the chemical analysis but also as a result of tasting berries,” says Émilien Boutillat Piper Heidsieck chef de cave. “In 2019, the perfect ripeness (phenolic and aromatic) was reached with quite a high level of sugar above 10deg° potential alcohol for Pinot Noir and Meunier and even more for Chardonnay; 10.5deg° and sometimes 11deg°. We had to be quite patient in order to reach the perfect balance between phenolic and aromatic ripeness; sugar and acidity. The end of August was amazing, in some areas the potential alcohol increased very quickly, rising 2deg° or more in just seven days. But this increase [in sugar] was not linked with the phenolic ripeness, so we had to be careful.”

Lanson’s head winemaker Hervé Dantan says: “We delayed harvest for a few days in Côte des Blancs, Vitryat and Montagne de Reims to wait for a true phenolic ripeness that was better around 11.0deg° potential alcohol with a malic acid level under 6 g/l.”

“This year (2019), there has been a lag between the ‘traditional’ ripeness and ‘phenolic’ ripeness, which is pretty rare up until now in Champagne,” notes Clément Pierlot head winemaker at Pommery. “We tasted a lot of berries [in the vineyard] this year to catch the moment when vegetal aromas change to fruity aromas. It was a vintage when it was vital for winegrowers to be in the vineyard constantly tasting the grapes.”

So deciding the exact best time to pick have never been more important for the Champenois. The Comité Champagne’s climate change dossier also lists common sense steps to prevent the grapes from getting hot. Picking at the coolest times of day (something mechanical harvesting would facilitate further), not leaving grape bins in the full sun, using light coloured bins – after six hours exposure to the sun there’s a 5degC temperature difference between a white and a red bin – and pressing as quickly as possible.

Of course, there are winemaking options to preserve freshness too, with blocking the malolactic fermentation on part or all of the base wines, the most obvious tool in the armoury. But advances in and changes to viticulture, like the wider gap between vine rows and adjusting canopy height and density, plus pinpoint weather forecasting are the short-term solution to the warming climate, providing temperatures don’t rise by more than 2degC. Beyond that and Chardonnay, Pinot Noir and Meunier’s role in Champagne may have to diminish.

Programme to develop new grape varieties

The CIVC started to actively focus on climate change back in 2003 — after the warning shot of Champagne’s earliest and hottest harvest on record had been fired. In the CIVC climate Dossier it notes that the warming climate has had a generally beneficial effect on the quality of the musts which may well continue if global warming is limited to a 2DegC rise. But if it rises further, other solutions, like entirely new grape varieties, may be needed.

Working in conjunction with the Institut Français de la Vigne et du Vin (IFV) and the Bureau Interprofessionnel des Vins de Bourgogne (BIVB), in 2010 it began a project with the French National Institute for Agricultural Research (INRA), specifically under the INRA-ResDur sustainable resistance programme, with in-situ evaluation of new varieties that could be included in the French catalogue.

Evaluation of the first series of varieties planted in 2011-12, resulted in four new varieties, two red and two white, being included in the catalogue: Voltis, Floreal, Artaban and Vidoc. Among their attributes, their principal claim to fame is that they are said to be resistant to both downy and powdery mildew and thus could help the Champenois (selection programmes are also taking place in Alsace, Bordeaux, Cognac, Provence and the Rhône) reduce the frequency of fungicides, insecticides and herbicides (herbicides are due to be banned entirely in Champagne by 2025).

A second series is being evaluated and a third series has just been planted and will be observed from 2020 onwards. A number of criteria are used to evaluate the varieties: phenology, agronomic behaviour, yield components, and wine quality, although they have not been selected in order to create a specific type of wine. At the same time, in 2014 the Comité Champagne launched a regional programme involving cross-breeding with Pinot Noir, Gouais, Chardonnay, Meunier, Arbane and Petit-Meslier.

As it spells out in the CIVC’s climate change dossier, there will be a 15-year selection process for the new grape varieties, divided into four stages. While stage one to find those seedlings containing the desired resistance genes is complete, stage two the intermediate selection, expected to last six years evaluating plants in situ in the Comité Champagne experimental vineyards and in Burgundy, only started in 2018 and during this stage, explains Thibault le Mailloux, CIVC director of communication, 200 plants will be reduced to 15-20 potential candidates. He expects the whole process to take at least another 10 years.