The 2010 Bordeaux vintage is "totally unusual", according to Chateau Mouton Rothschild winemaker Philippe Dhalluin.

Speaking to Decanter at the beginning of the 2010 Bordeaux en primeur barrel tastings, Mr Dhalluin explained that the latest Chateau Mouton Rothschild blend contains 94 per cent Cabernet Sauvignon grapes - a much higher proportion than normal.

"The Cabernet was of such high quality it was difficult for the Merlot to compete," he told the publication.

Mr Dhaullin went on to explain that the 2010 Bordeaux is unusual as the grape harvest experienced extremely dry weather conditions, yet overall temperatures remained low.

This resulted in grapes that were rich and high in acidity, tannins and alcohol.

However, some concern has been expressed that the alcohol content in Bordeaux wines is becoming too high.

Top oenologist and owner of the Chateau Leoville Poyferre estate in St Julien, Didier Cuvelier, believes that alcoholic content of 15 per cent is threatening the traditional character of Bordeaux.