Can you name the three key elements in champagne production? Fruit, sure. Yeast, sure. But the third? Not so easy.
But Ruinart’s cellarmaster, Frederic Panaïotis, has the answer.
‘Oxygen control is critical in Champagne,’ he says. ‘People are working on it more and more. It’s very important I think.’
Speaking to an audience of sommeliers at this year’s Ruinart Sommelier Challenge in London, Panaïotis claimed that oxygen was the ‘often overlooked’ aspect of quality Champagne production.
He even went on to say that there could be a scientific basis for ageing Champagne vertically – sur pointe – rather than horizontally – sur lattes, and that, after 12 years of research, Ruinart has switched to ageing its champagnes under cork, rather than crown cap.
According to Panaïotis, oxygen levels are partly a stylistic decision. Ruinart, for instance, is more reductive, with dissolved oxygen levels of just 4mg/litre after second fermentation, while Selosse, for instance, is much more oxidative (14mg/l).
But myriad factors can impact this, and not just when wine comes into contact with air, during pressing, fermentation and wine transfers.
‘I like to say that champagne is magic,’ said Panaïotis, ‘but it still has to follow the rules of physics. [Even for bottles closed with a crown cap] oxygen will tend to get inside and carbon dioxide will tend to escape, although those quantities are very small.’
How quickly this happens depends on the closure. Bottles with a crown cap will see an oxygen intake after 10 years of 1.5mg/l (low permeability) to 18mg/l (high).
But in this case lower isn’t necessarily better.
‘To me, low permeability with non-vintage makes no sense unless you really want something tight and reductive,’ explained Panaïotis.
He has also found a clear difference between champagnes aged horizontally, and those kept ‘sur pointe’, or upside-down.
In the latter case, dead yeast cells gather near the closure, providing a partial barrier to oxygen ingress.
‘This is what the old guys were doing in Champagne,’ said Panaïotis. ‘They didn’t know why – they had no way to measure it. But they had time to observe things and they realised that it made a difference.’
As a result, to counter oxygen ingress, Ruinart’s ‘library’ champagnes are now all being aged sur pointe.
They’re also, perhaps controversially, being aged under cork.
This decision – taken in 2010 – was the result of 12 years of research, which led Panaïotis to the conclusion that corks are better than crown caps at preventing oxygen intake during long ageing, because they become a more efficient barrier after six or seven years.
Of course there will be downsides, not least the risk of TCA, some bottle variation and the fact that cork brings flavour (through phenolics) to the wine, but Panaïotis is unmoved.
‘There will be some variations, but it’s better for us,’ he said.