To qualify for the new vin méthode nature classification created by the French Gov. the grapes must carry organic certification, be hand-picked and fermented using indigenous yeasts. Methods which are banned during the winemaking process include thermovinification, reverse osmosis, flash pasteurization and cross-flow filtration.
Up to 30 mg/L of sulfur dioxide is permitted after fermentation. Wines with no added sulfites may be labelledvin méthode nature sans sulfites ajoutés(natural method without added sulfites) while those with a post-fermentation addition can carry thevin méthode nature avec moins de 30 mg/l de sulfites ajoutés (natural method with less than 30 mg/l added sulfites) tag.