Rising temperatures require new techniques in Champagne

Last night (25.11.09), at a London tasting of Lanson vintage Champagne back to 1976, host Tom Stevenson said that the famed French sparkling wine region was getting warmer, while the extreme 2003 harvest was “a wake up call” for producers.

Looking at statistics back to the 50s, he showed that average temperatures were rising causing alcohol levels to increase and acidity to fall in the wines being produced.

Stevenson pointed out that the Champagne region’s average temperature during the growing season was 14.3ºC between 1951 and 1990, but up 0.7ºC to 15ºC on average for the following ten-year period.

For the current decade, although final figures are yet to be released, he said, “I think there will be a bigger jump”.

In particular, Stevenson said the 2003 vintage was a wake up call for the Champenois. Summertime temperatures were so high there were 14,000 heat-related deaths in France by August.

“However,” he added, “while most think of 2003 as a year of drought, it in fact started with very low temperatures (-11ºC) and ended with floods. It was a year of extremes.”

As for the resulting Champagnes, these had the “lowest acidity and highest pH on record,” with an average pH of 3.28, but some wines were as high as 3.7. These he compared to an average pH of 3.17 in another famously hot year, 1976.

“Everyone should have made a vintage in 2003,” said Stevenson, “because it was the start of something that will happen more regularly in the future and it gives one an opportunity to look back and learn.”

“Even those who made a vintage but didn’t release it will find it an important baseline,” he added.

He then considered the possible solutions for a year like 2003, including varying the sugar content of the dosage, acidifying, using different clones and methods of training and pruning in the vineyard, before finally, and importantly, employing non-malolactic fermentations.

Non-malolactic fermentation, notably practiced by Lanson, as well as Bollinger, Gratien and Krug, prevents a drop of pH of between 0.1 and 0.3 he explained, as well as “assisting potential ageing, particularly post-disgorgement.”

Concluding, considering rising temperatures during the growing season in Champagne, he said, “For the future there will be a swing to the non-malolactic style.”

For an extensive analysis of climate change in Champagne see October’s drinks business, pages 46 to 50.

Patrick Schmitt, 26.11.09