(AFP) - Organic wine growing is gaining ground in France where a Bordeaux Sauternes "grand cru", the highest classification level, has just been awarded the official biological farming (AB) logo. Chateau Guiraud 2011 will be the first of the region's top Sauterne wines to carry the logo, some 15 years after one of its owners, Xavier Planty, first started to experiment with organic farming. The sweet white wine -- made from a mixture of semillon and sauvignon blanc grapes -- has been grown for hundreds of years in this southwestern French region, but production today involves neither artificial pesticides, nor fertilisers, nor herbicides.