The shape of the aging vessel might not fight climate change, but it does impact the finished wine.
A top Burgundy winemaker has mocked claims that production vessels are helping winemakers grapple with the climate crisis. Wine producers in France and elsewhere in Europe, are increasingly using rounded or oval big wooden foudres vats to replace smaller barriques, as well as rounded concrete eggs and amphorae.
Champagne producer Louis Roederer is now using a mix of stainless steel and foudres in wine production as result of trials conducted in the wake of the impact of climate change on wine production. "Preserving freshness" is a phrase often used by producers when discussing the merits of using big foudres or indeed concrete eggs.
Bordeaux producers, including Saint-Émilion's Château Bellefont-Belcier, have even said the use of foudres helps to maintain acidity levels in wines. Emmanuelle Fulchi, Bellefont-Belcier's winemaker, told Wine- Searcher that use of large 40 hectoliter foudres was helping to ensure pH levels are kept at adequate levels during the aging of wine. "There is less reduction of tartaric acid in foudres – which we use to age a third of our wines," Fulchi said.
But, in a broadside against Bordeaux producers, Burgundy winemaker, and director at Verget, Julien Desplans dismissed the claim.
"That's nonsense! In Bordeaux, there is always a need to justify wine bottle prices by saying: 'I have a new winery, I have new tanks, I've a bigger triage table than my neighbor'. It is as if I said my wines are twice as better now as because I have doubled the size of my sorting table. I don't think the shape or type of vessel modifies pH levels," he told Wine-Searcher, adding that parameters including the quality of grapes and how they are pressed and fermented were relevant factors, rather than the type of aging vessel used, be it tank or wood.
Meanwhile, Champagne producer Lanson said the motive for investing in foudres was unrelated to the impact of climate change on freshness and acidity levels on wine.
"When we invested in foudres in 2014, it was nothing to do with global warming. Foudres, which bring aromatic changes and complexity to wines, are used to age our reserve wines over many years. We have not noticed any change in acidity levels during the aging of wines. For us, aging reserve wine in foudres gives them texture and aromas, like dried fruit, vanilla, and candid citrus," Lanson's cellar master, Hervé Dantan, told Wine-Searcher.
However, Jérôme Viard, co-owner of artisanal cooperage Tonnellerie de Champagne said demand for oval or round horizontal foudres had doubled since 2020, partly in response to the impact of changing climate on wine production.
Foudres are predominately used in Champagne for reserve wines. The dimension and shape of foudres ensures that that there is less of an impact of oak on wine. However, Viard said demand for foudres was growing in southern European regions more acutely affectedly by rising temperatures.
"Producers in the Bordeaux, Rhône and Languedoc-Roussillon are investing in barrels and foudres with more volume to preserve freshness in wines," Viard said.
To illustrate his point, he said that his company was exporting foudres to southern Europe including Spain and Greece, but smaller barrels to cool climate regions like England.
Over the past two years, Tonnellerie de Champagne, which predominately serves the Champagne market, has developed new foudre types that incorporate either stainless steel or glass to the wood, in which only toasted wood is exposed to aged wine.
"These new foudres designs allow the wine to be less impacted by oaky flavors and aromas, as well as ensuring that freshness and tension is maintained in wines," Viard said.
Following a series of production trials, Jean-Baptiste Lécaillon, winemaker at Champagne producer Louis Roederer said he was making more use of oak in production, but predominantly retaining stainless steel to ferment wines.
Speaking to French newspaper Le Monde in December 2023, Lécaillon, said: "Climate change is making wines increasingly spherical [round] when vinified and aged in stainless steel, whereas wood helps to stretch wines. So, I'm a proponent of a return to the use of wood, while retaining stainless steel as a fundamental element of neutrality," he said, adding that when faced with perilous climatic upheavals, it is preferable for a winery to "develop a maximum number of tools so as to be able to adapt them to each vintage".
Lécaillon said Roederer was using wood to foudres to ferment 30 percent of wines.
The horizontal alternative
Burgundy’s Verget, however said that a changing climate had not prompted it to make changes to the type of vessels employed in wine production.
Since 1990, Verget has been using bespoke rounded, horizontal tanks to ferment all its white wines. "We got rid of vertical inox tanks, after the use of horizontal ones to ferment and age white wines proved successful," said Desplans.
Jean-Marie Guffens, owner of Verget, and the late Denis Dubordieu, the renowned Bordeaux winemaker who raised the profile of the region's white wines, dreamt up the idea of making rounded horizonal stainless steel tanks, but each of them ended up designing their own bespoke tanks. At Verget, a neutral gas is injected into the tank to re-suspend and enable reduction for the finest lees, following fermentation. The movement of lees with the wine is continuous, whereas in vertical tanks, lees move from the top downwards in one movement.
"The different contact with the lees results in fruitier aromas and fine reductions which can lead to a more marked sensation of freshness; however, I don't think the shape modifies pH," Desplans said.
On Pico Island in the mid-Atlantic, Portuguese producer, the Azores Wine Company, also uses dozens of rounded, horizontal stainless tanks to ferment and age white wines.
Antonio Maçanita, one of Portugal's most innovative winemakers, says he was inspired to design his own tanks, after spotting milk tanks on delivery trucks in the Azores.
Working with delicate local white grape varieties to make some of globe's most luminous, smoky, and saline terroir-focused wines from grapes grown on lava fields, has required tailored production solutions, to ensure that the unique terroir of Pico Island is reflected in wines. Using oak could lead to oxidation or the addition of unwanted aromas in wines, Maçanita pointed out.
Using his tanks allows the lees of wine spread through the tanks brings depth, richness, and texture to wines. Compared to vertical inox tanks, rounded, horizontal ones allow much more contact and movement between liquid and solid matter, ensuring the lees are not packed in.
"There are none of the metallic or unwanted flavors, which batonnage [lees stirring] can bring in long aging of wine. This method also natural releases gluthuthione, an antioxidant compound. The entire process can be carried with much lower sulfur, as it works as an antioxidant protecting the wine," he told Wine-Searcher.
Maçanita said there was there's much more flow of the lees in rounded, horizontal tanks, when compared to aging white wine in amphora clay. Maçanita uses the same horizontal tanks to make whites wines at Maçanita Vinhos in the Douro Valley.
Meanwhile, Desplans admitted that bespoke rounded horizontal tanks were considerably more expensive, than concrete eggs, (which producers also used for lees ageing).
Rounded horizontal stainless-steel tanks remain a rarity in Europe, but their production benefits have sparked the interest of cool climate winemakers in England, including Dermot Sugrue and the producer Everflyht, where still wine production is increasing.