The Berthier brothers are based in the village of Sainte Gemme en Sancerrois a few kilometres to the north.of the village of Sancerre itself. In addition to their vineyards on the western bank of the river Loire in the Cher department, from which their Sancerre wines are produced, they also own vineyards on the eastern bank of the river in the Nievre department from which their Pouilly Fume and Coteaux de Giennois are produced. The Coteaux du Giennois appellation is a narrow line of vineyards on the eastern bank of the Loire north of Pouilly sur Loire whose vineyards grow on a ridge facing south-westwards over the river itself, thus meaning that the vines are well-drained and the grapes ripen better. 

Sauvignon Blanc predominates these days on both side of the river although approximately 35% of the vineyard area overall is planted with Pinot Noir which makes the Sancerre rose & rouge, both of which are popular in the region and the Paris area.