The Chardonnay grapes from the six Grand Cru villages of the Côte des Blancs: Le Mesnil sur Oger, Oger, Avize, Cramant, Chouilly, Oiry and Vertus in Premier Cru with parcels of Barilliers, Faucherets and les Monts Ferrés. Duval-Leroy was one of the first Champagne houses to be HVE3 certified, employing many sustainable practices. Measures are taken to combat the run-off of rainwater to limit the pollution of underground and superficial water; grass cover crops are grown, and processes to combat soil erosion are employed. Biodiversity is positively encouraged; sustainable fertilisers are used, and sexual confusion of predators takes place instead of insecticides. The plots and weather conditions encountered are carefully monitored, with soil testing and cartographic, computerised methods in place for full traceability of products used in the plots. Above all, preventative measures are in place to minimise the use of products, which, if necessary, are carefully chosen to have the least impact on the environment. The grapes are hand-harvested.